INSTRUCTION MANUAL FOR - DCU

Fracture Mechanics - Analysis Instruction Manual

Document MA11_1

Date 15/09/08

Phoenix Calibration & Services Ltd Brick Kiln Street, Harts Hill, Brierley Hill, West Midlands, DY5 1JG, UNITED KINGDOM Tel. No. +44 (0)1384 480545 Fax No. +44 (0)1384 480602 E-mail: [email protected] Web site: http://www.phoenixcalibration.co.uk

Phoenix Calibration & Services Ltd

Trademark acknowledgements MS-DOS and Microsoft Windows are trademarks of Microsoft Corporation. IBM is a trademark of the International Business Machines Corporation.


CONTENTS 1.

INTRODUCTION.........................................................................................................................................3

2.

RUNNING THE PROGRAM - AN EXAMPLE ........................................................................................4 FIGURE 1. THE MAIN SCREEN ..............................................................................................................................4 FIGURE 2. THE DETAILS SCREEN .........................................................................................................................5 FIGURE 4. THE CHECK LIST SCREEN ....................................................................................................................8 FIGURE 5. THE GRAPH SCREEN............................................................................................................................9

3.

THE MAIN SCREEN .................................................................................................................................11 RETRIEVE RESULTS FILE, FILE NAME, AND FILE PATH ......................................................................................11 MODULUS CHECK ..............................................................................................................................................11 PART NUMBER ...................................................................................................................................................11 SPECIMEN TYPE .................................................................................................................................................11 EFFECTIVE WIDTH (W) .....................................................................................................................................12 TOTAL WIDTH (C).............................................................................................................................................12 THICKNESS (B)..................................................................................................................................................12 CRACK LENGTH .................................................................................................................................................12 SPAN ..................................................................................................................................................................12 FINAL COMPLIANCE ...........................................................................................................................................12

4.

THE MAIN SCREEN MENU BAR ..........................................................................................................13 FILE MENU -> OPEN FRACTURE FILE .................................................................................................................13 FILE MENU -> OPEN PRECRACKING FILE ............................................................................................................13 FILE MENU -> PRINT SETUP... ............................................................................................................................13 FILE MENU -> EXIT ............................................................................................................................................13 THE FILE MENU “EXIT”OPTION CLOSES THE PROGRAM......................................................................................13 TEST STANDARD MENU ......................................................................................................................................13 OPTIONS MENU -> PREFERENCES.......................................................................................................................13 FIGURE 6. THE PREFERENCES FORM ..................................................................................................................14 REFERENCES MENU ............................................................................................................................................14 ABOUT MENU .....................................................................................................................................................14

5.

THE THUMBNAIL SCREEN ...................................................................................................................15 NO STABLE CRACK EXTENSION BOX, ................................................................................................................15 9 MEASUREMENTS BUTTON,...............................................................................................................................15 5 MEASUREMENTS BUTTON ................................................................................................................................15 CRACK LENGTH AND AO VALUE ........................................................................................................................15 STABLE EXTENSION AND ∆A VALUE (BS 7448) .................................................................................................15 PRINT .................................................................................................................................................................16 CANCEL .............................................................................................................................................................16 OK.....................................................................................................................................................................16

6.

THE GRAPH SCREEN..............................................................................................................................17 RE-SCALE...........................................................................................................................................................17 REPORT ..............................................................................................................................................................17 CANCEL .............................................................................................................................................................17 UPPER AND LOWER LOAD REFERENCE LEVELS AND THE SLOPE OF THE CURVE .................................................17 PLATEAU DETECTED ..........................................................................................................................................17 KIC VALUE ..........................................................................................................................................................17 THE “?” BUTTON ................................................................................................................................................18 CTOD AND J BUTTONS ......................................................................................................................................18

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FIGURE 7. THE GRAPH SCREEN SHOWING ONE POP-IN. ......................................................................................18 POP-IN DISPLAY..................................................................................................................................................18 FIGURE 8. THE POP-IN LIST.................................................................................................................................18 7.

THE GRAPH SCREEN MENU BAR .......................................................................................................20 FILE MENU -> REPORT .......................................................................................................................................20 FILE MENU -> CLOSE .........................................................................................................................................20 EDIT MENU -> DATA... .......................................................................................................................................20 EDIT MENU -> RE-SCALE... ................................................................................................................................20 OPTIONS MENU -> SHOW OFD LINE ...................................................................................................................20 OPTIONS MENU -> SHOW POP-IN LINES..............................................................................................................20 OPTIONS MENU -> SHOW POP-IN LIST ................................................................................................................21 OPTIONS MENU -> IGNORE ALL POP-INS ............................................................................................................21 OPTIONS MENU -> ANALYSE FOR CTOD ...........................................................................................................21 OPTIONS MENU -> ANALYSE FOR J.....................................................................................................................21 OPTIONS MENU -> WHY NOT VALID ? ...............................................................................................................21 REFERENCES MENU ............................................................................................................................................21

8.

APPENDIX - AN INTRODUCTION TO WINDOWS ............................................................................22

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1.

INTRODUCTION

This manual describes the operation of the PS Fracture Analysis Program which is one part of a three program suite for Fracture Mechanics testing to standards including BS 7448 Part 1 1991. The other two programs in the suite are the Precracking and Fracture programs. The Precracking Program is used to grow a precrack in the specimen, after which the Fracture Program loads the specimen to final fracture or plastic collapse. Finally the Analysis Program uses the results obtained from the first two tests to calculate the opening mode plane fracture toughness (KIc), critical crack tip opening displacement (CTOD), or critical J fracture toughness values of the specimen. The software may be used with either Compact Tension Specimens (CTS) or three-point bend Single Edge Notch (SEN) specimens. Although the three programs are designed to work as an integrated suite, each may be used separately with data from other sources which provides for maximum flexibility. The Analysis Program has the facility to print the specimen parameters for record purposes. The test results data are placed in a standard comma-separated variable (CSV) format ASCII file which may easily be imported into other programs such as a spreadsheets, word processors, or data analysis packages. The Precracking and Fracture programs work in conjunction with a PS Control System and servo-hydraulic testing machine. The Analysis Program only operates on the results data files, so may be used without a test rig. All Phoenix Calibration & Services Ltd applications programs are designed to run within the Windows environment on an IBM compatible personal computer.

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2.

RUNNING THE PROGRAM - AN EXAMPLE

The Analysis Program has many possible options which are explained in detail in the sections which follow. In order to familiarise the user with the basic principles of the software, this example section describes a typical test which might be performed. While it may not correspond exactly to your own testing methods, please read this section carefully. The small amount of time required will give the new user a good overview of the features available and how to run the software. Once Windows is running, start the program by selecting it from the Start button -> All Programs -> Phoenix Services -> Fracture Analysis or double clicking the icon in the Phoenix Services folder. The program will start with the Main Screen which is shown in figure 1 (with no parameters entered).

Figure 1. The Main Screen When the Main Screen first appears the selected button is “Retrieve Results File”. The Fracture Program produces a results file which may contain all of the information required on the Main Screen. Clicking the “Retrieve Results File” button opens a standard dialogue box which will allow a “.daf” results file to be retrieved. Any or all of the parameter boxes on the Main Screen will then contain values from the file. If any values are not entered it is because

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they were not entered in either the Fracture Program, or even earlier in the Precracking Program, and they will therefore need to be entered by hand now. It is also possible to use this program to analyse data from sources other than the Fracture Program in which case no “.daf” file exists which can be imported, and so all of the screen parameters will need to be typed in. For the purpose of this example it is assumed that a suitable results file exists, and that the Main Screen parameters will not need to be entered manually.

Figure 2. The Details Screen If the Main Screen parameters are all shown correctly, click the “Analyse Data” button. If any of the parameter entry boxes are not correctly completed a warning message will appear and it will not be possible to go to the next screen until the problem has been corrected. Once all of the data is correct the program moves on to the Details Screen (figure 2). Like the Main Screen, the Details Screen will be completed with all parameters already entered if a complete “.daf” results file has been retrieved. If no file is retrieved, or it is incomplete, some or all of the parameters may need to be typed in. Once the screen has all of the required data present, click the “OK” button to move on to the next screen. (Clicking “Cancel” at this stage returns the user to the Main Screen.) The next screen is the “Thumbnail” Screen (figure 3).This screen allows the user to enter the various crack length measurements. For BS 7448, the first requirement is to decide whether or not stable crack extension has occurred during the fracture part of the test as this determines the amount of data which must be entered. If there has been stable crack extension, nine measurements of the crack length and stable extension are required by BS

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7448, and the display will appear as in figure 3a. In this case the “5 measurements” button will be inoperative.

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Figure 3a. Stable crack extension (BS 7448).

Figure 3b. No stable crack extension, 9 measurements (BS 7448).

Figure 3c. No stable crack extension, 5 measurements.

Figure 3. Three possible "Thumbnail" screens

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If no stable crack extension has occurred, click in the box marked “No Stable Crack Extension”. The box will then be checked, and the display will no longer show stable extension measurement boxes (figure 3b). If the “No Stable Crack Extension” box has been clicked, the option will be given to enter either nine or five measurements of crack length, as selected by the “9 measurements” (figure 3b) or “5 measurements” buttons (figure 3c). Having selected the type of crack extension and number of measurements, enter the values for Crack Length (and Stable Extension) in the column(s) provided. After entering all of the required values the weighted averages are calculated by the program and displayed in the boxes at the bottom of the columns. The aO/W value will also be calculated and displayed. It will normally be shown in black, unless it is outside the relevant range (0.45 to 0.55 for BS 7448) in which case it will be shown in red. Once the Thumbnail Screen is complete it may be printed by clicking the “Print” button. The “Cancel” button will return the user to the Main Screen. Clicking “OK” causes the program to move on to the Check List Screen (figure 4).

Figure 4. The Check List Screen The first four parameters on this screen are completed automatically from the values already entered. The program automatically confirms the status of the following values :• • • •

whether or not the aO/W ratio is within the correct range that the difference between crack measurements is acceptable that the position of the precrack front is between the correct limits that the Kf value is within limits.

The remaining check boxes need to be completed by the user. These are :• To confirm that the notch and precrack were within an envelope of W/16 and 30 degrees

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• To confirm that multi-plane precrack and fracture are not present • To confirm that the precrack plane was within 10 degrees of the crack extension plane. The 0.2% Proof Strength and Young's modulus values are also shown on the screen for confirmation. If both are available to the program the σYS/E value will be calculated and displayed. When the Check List Screen has been completed, click “OK” to continue. Clicking “Cancel” will return the user to the Main Screen. The next screen is the Graph Screen shown in figure 5. This displays the graphical data which was obtained during the fracture phase of testing. If the data exhibits pop-ins, a window will appear below the main graphical display which lists them. Please refer to section 6 for further details. For the sake of this example it will be assumed that no pop-ins are present.

Figure 5. The Graph Screen The load-extension graph may be re-scaled in both axes by clicking the “Re-scale” button which opens the re-scaling control window containing a slider control for each axis. Reposition the sliders to give the required scaling, then click “OK”. The upper and lower load values will be marked by horizontal dotted lines on the display. These load values mark the portion of the curve over which the slope value (which is displayed in the upper right portion of the screen) is calculated. The load values are displayed on the left of the screen with the corresponding extension values on the right of the screen.

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Buttons next to these load reference levels allow them to be moved up or down. The marked slope will change accordingly. Users without a mouse should note that the upper load reference may be moved using the Page Up and Page Down keys, and the lower reference moved with Shift + Page Up or Shift + Page Down. The “Plateau detected” box will be checked if the software has automatically detected a plateau in the curve. (Plateau detection is under control of the parameters on the Options menu of the Main Screen.) The outcome of the analysis differs depending on whether or not the load-extension curve exhibits a plateau or pop-ins. If the user feels that there is a plateau which the program has not detected, it is possible to click the box manually. If the program can calculate a valid KIc value it will do so, and display it in the box near the bottom left of the screen. If the KIc value is not valid it will say so and the user may click the “?” button to see a pop-up window which lists the reasons for the invalidity. If it is not possible to calculate a valid KIc value the user may click on the “CTOD” or “J” buttons (if available) to determine values of critical crack tip opening displacement (CTOD) or critical J fracture toughness respectively. Clicking the “Report” button prints a final report.

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3.

THE MAIN SCREEN

This section describes the features of the Main Screen (figure 1) in detail, with the exception of its menu bar which is dealt with in section 4. If a results file is imported as described in the “Retrieve Results File” section below, all of the information on the Main Screen will be completed automatically from the file. If the Analysis Program is used “stand-alone” with data from some other source then all of the screen parameters will need to be entered by hand. Retrieve Results File, File Name, and File Path The Analysis Program is normally used in conjunction with the PS Precracking and Fracture programs, in which case it imports most of its data from the combined results of these tests. These are normally placed in files with “.daf” extensions in the “C:\PS\Results” folder. The Analysis Program can import such a file via the “Retrieve Results File” button, which will open a standard dialogue box allowing the required path to be entered. If the file path has already been entered it is only necessary to enter a file name in the “Results File Name” box. The file extension should not be entered as it is always forced to “.daf” (for data - fracture). If a complete results file is imported, all of the parameters on the Main and Details Screens will be automatically completed from the file and no further user input will be required before the Thumbnail Screen. Modulus Check The “Modulus Check Limits” box contains Upper and Lower Load values. The specimen modulus is calculated during the Graphical phase of the program by projecting a line through the two points where the load-extension curve crosses the upper and lower levels set in the two boxes. If the “Slope” option is enabled in the Options menu this line will be drawn on the display during the Graphical Display section of the test. The user may change the Upper and Lower Load values to suit the actual data. The peak recorded load value is displayed in the box to aid the user in selecting a suitable set of values. The values may also be changed during the Graph phase of program execution. Part Number Unlike the other parameters shown on the main screen, the “Part Number” box need not be completed in order to run a test. The box is provided only for convenience, and any batch, job, or part number entered here will be printed at the end of the test. The Part Number is also shown in the References Table, and may be entered from the References menu (see Section 4). Specimen Type The PS Fracture Analysis Program may be used either with compact (“CTS”) or three-point bend (“SEN”) specimens as selected from the drop-down box. If an SEN type specimen is in use then the span of the bend fitting will need to be entered in addition to the specimen width and breadth.

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Effective Width (W) Total Width (C) Thickness (B) Crack Length For specific details of how these dimensions are defined please refer to the appropriate standard as they vary with specimen type. As a general reminder, however, the Effective Width (W) of the specimen is measured in the direction in which the crack is to be grown, the Thickness or Breadth (B) is measured in the direction along the crack tip or notch end. Span This parameter may only be entered if a three point bend type specimen is selected, in which case this dimension is the distance between the supporting rollers of the specimen fitting. Final Compliance The final compliance figure is the compliance measured at the end of the precracking phase of testing.

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4.

THE MAIN SCREEN MENU BAR

The following section describes the features to be found on the pull-down menus at the top of the Analysis Program Main Screen (figure 1). Users who wish to access the menu bar without a mouse should note that the “Alt+key” access keys which may be used within the main part of the screen do not give access to the menu bar. To reach the menu bar use the function key F10. Once the menu bar is accessed, the menu selection may be made either by pressing a short-cut key (e.g. “F” to access the File menu) or by using the cursor keys. File menu -> Open Fracture File The “Open Fracture File” option allows the retrieval of a Fracture Program “.daf” data file. It is an alternative to clicking the “Retrieve Results File” button on the Main Screen. File menu -> Open Precracking File The “Open Precracking File” option allows the retrieval of a Precrack Program “.dat” data file. This can be used if precracking is done with the PS software, but fracture is done by some other method. File menu -> Print Setup... The “Print Setup...” option allows printer drivers and setups to be chosen using the standard Windows printer setup dialogue boxes. File menu -> Exit The File menu “Exit”option closes the program. Test Standard menu The “Test Standard” option allows a choice of recognised standards for the test to be performed with. Choices include BS 7448 and ASTM E 399. This governs what range of values for certain parameters are acceptable and what type of specimen may be used. Options menu -> Preferences... Selecting “Preferences” from the Options menu opens a window containing various graph line options which are toggled on or off by clicking in the boxes. If a box is checked the option is enabled, if the box is blank the option is disabled. Selected lines will be drawn on the Graph Screen later in the analysis. They may also be turned on or off from the Graph Screen via the Options menu on that screen. The Options window also contains a plateau detection control value which specifies an extension range. If, during any part of the load/extension curve, the load does not vary by more than 1% over this range of extension, then the program regards that section of the curve as a plateau and the “Plateau detected” box will be checked when the Graph Screen is reached (see the Graph Screen section 7). The larger the extension range specified in this box, the flatter the curve must be before a plateau is automatically detected. Note that the user can override the automatic plateau detection at the Graph Screen stage.

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Figure 6. The Preferences Form References menu The References Table contains important test details such as material specification etc. which may be entered by the user and printed with the results at the end of the test. To enter values into the table, select the “Setup” option from the References menu. This will open the table for text entry. When the values have been entered, click the “OK” button. Entering any information into the references table is optional. To print a copy of the references table to the printer, select the “Print” option from the References pull-down menu. About menu The About menu displays a box containing the Analysis Program version number, as well as information to help the user to contact Phoenix Calibration & Services Ltd. in the event of a query.

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5.

THE THUMBNAIL SCREEN

No Stable Crack Extension box, 9 measurements button, 5 measurements button Three possible Thumbnail Screens as shown in figure 3. These screens allow the user to enter the various crack length measurements. For BS 7448, the first requirement is to decide whether or not stable crack extension has occurred during the fracture part of the test, as this determines the amount of data which must be entered and displays the appropriate screen. If there has been stable crack extension the “No Stable Crack Extension” box should be left unchecked. If stable crack extension has occurred then nine measurements of the crack length and stable extension are required by BS 7448, and the display will appear as in figure 3a. In this case the “5 measurements” button will be inoperative. If no stable crack extension has occurred, click in the box marked “No Stable Crack Extension”. The box will then be checked, and the display will no longer show stable extension measurement boxes (figure 3b). If the “No Stable Crack Extension” box has been clicked, the option will be given to enter either nine or five measurements of crack length, as selected by the “9 measurements” (figure 3b) or “5 measurements” buttons (figure 3c). The ASTM standards only require 5 measurements to be taken. Crack Length and aO value The values for Crack Length should be entered in the column provided. After entering all of the required values the weighted average is calculated by the program and displayed in black in the “aO” box at the bottom of the column. In this case the words “weighted summation” appear below the calculated value. It is also possible to click in the aO box and enter a value directly, bypassing the program's calculated value. In this case the value will be shown in blue and the words “entered value” appear below it. The crack length values will be greyed-out to indicate that they have not been used to derive the aO figure displayed. To revert to using the entered values, enter zero in the aO box, then click in any of the crack length entry boxes. The aO/W value will also be calculated and displayed. It will normally be shown in black, unless it is outside the relevant range (0.45 to 0.55 for BS 7448) in which case it will be shown in red. Stable Extension and ∆a value (BS 7448) If stable crack extension has occurred, the values for the extension should be entered in the column provided. After entering all of the required values the weighted average is calculated by the program and displayed in black in the “∆a” box at the bottom of the column. In this case the words “weighted summation” appear below the calculated value. It is also possible to click in the ∆a box and enter a value directly, bypassing the program's calculated value. In this case the value will be shown in blue and the words “entered value” appear below it. The stable extension values will be greyed-out to indicate that they have not been used to derive

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the ∆a figure displayed. To revert to using the entered values, enter zero in the ∆a box, then click in any of the stable extension entry boxes. Print Once the Thumbnail Screen is complete it may be printed by clicking the “Yes” button when the “Print this form” dialogue box appears. Cancel The “Cancel” button will return the user to the Main Screen. OK Clicking “OK” causes the program to move on to the Check List Screen (figure 4).

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6.

THE GRAPH SCREEN

The Graph Screen shown in figure 5. This displays the graphical data which was obtained during the fracture phase of testing, and is the final screen of the program. Re-scale The graph may be re-scaled in both axes by clicking the “Re-scale” button which opens the re-scaling control window containing a slider control for each axis. To re-scale an axis, move the slider control for that axis until the required maximum scale is shown, then click “OK”. This feature is also available from the “Options” menu. Report Clicking the “Report” button prints a final report. This feature is also available from the “File” menu. Cancel Clicking the “Cancel” button returns the user to the Main Screen without further computation of results. Upper and Lower Load reference levels and the Slope of the curve The upper and lower load values are marked by horizontal dotted lines on the graph. These load values mark the portion of the curve over which the slope value (which is displayed in the upper right portion of the screen) is calculated. The slope value is required as part of the KIc calculation. The load values are displayed on the left of the screen with the corresponding extension values on the right of the screen. Buttons next to these load reference levels allow them to be moved up or down. The marked slope will change accordingly. Users without a mouse should note that the upper load reference may be moved using the Page Up and Page Down keys, and the lower reference moved with Shift + Page Up or Shift + Page Down. Plateau detected The outcome of the analysis differs depending on whether or not the load-extension curve exhibits a plateau. The program has the ability to determine automatically whether or not a plateau exists. When the Graph Screen first appears the “Plateau detected” box will be crossed if the software has automatically detected a plateau in the curve. If the user feels that there is a plateau which the program has not detected, it is possible to click the box manually. Plateau detection is under control of the parameters on the Options menu of the Main Screen. See the Main Screen menu bar Section 3 for details. KIc value If the program can calculate a valid KIc value it will do so, and display it in the box near the bottom left of the screen.

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The “?” button If the program cannot derive a valid KIc value, clicking the button marked “?” will open a pop-up window listing the reason or reasons for the invalidity. This feature is also available from the “Options” menu. CTOD and J buttons If it is not possible to calculate a valid KIc value the user may (if the standard allows) click on the “CTOD” or “J” buttons to determine values of critical crack tip opening displacement (CTOD), or critical J fracture toughness respectively. (Note for example that the “J” option is not available for straight notch compact specimens in the BS 7448 standard.) Pop-in display If the load-extension data exhibits pop-ins, when the Graph Screen is displayed a list of popins will appear underneath it. The graph will display the pop-ins as shown in figure 7, and the pop-in list appears as in figure 8.

Figure 7. The Graph Screen showing one pop-in.

Figure 8. The pop-in list.

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If the user feels that a particular pop-in is not significant click in the box marked “Ignore” and that pop-in will not be assessed by the program. Alternatively it is possible to ignore all popins from the Options menu. A “Print Pop-in List” button is provided so that a copy of the list may be obtained. This list may also be printed from the Options menu, Show Pop-ins feature.

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7.

THE GRAPH SCREEN MENU BAR

The following section describes the features to be found on the pull-down menus at the top of the Analysis Program Graph Screen (figures 5 & 7). Users who wish to access the menu bar without a mouse should note that the “Alt+key” access keys which may be used within the main part of the screen do not give access to the menu bar. To reach the menu bar use the function key F10. Once the menu bar is accessed, the menu selection may be made either by pressing a short-cut key (e.g. “F” to access the File menu) or by using the cursor keys. File menu -> Print Setup... The “Print Setup...” option allows printer drivers and setups to be chosen using the standard Windows printer setup dialogue boxes. File menu -> Report This option prints a hard copy of the final report. File menu -> Close The File menu “Close” option returns the user to the Main Screen. Edit menu -> Data... The “Edit menu -> Data” option allows access to the data points used to plot the load/extension graph. This feature may be used simply to inspect the data, or to edit the values. This may be required if the data was from a third-party source rather than having been retrieved from a Fracture Program “.daf” file. Edit menu -> Re-scale... The graph may be re-scaled in both axes using the Edit menu Re-scale option which opens the re-scaling control window. This contains a slider control for each axis. To re-scale an axis, move the slider control for that axis until the required maximum scale is shown, then click “OK”. This facility is also available directly by clicking on the “Re-scale” button on the Graph Screen. Options menu -> Show OFd Line The “OFd” line is a line drawn through the origin at a slope less than the slope of the initial part of the test results curve. For a full explanation please refer to BS 7448. The Options menu “Show OFd Line” option allows the user to select whether or not this line is shown on the display. If the option is selected the line is displayed in green. Options menu -> Show Pop-in Lines This option turns the display of pop-in lines on or off. If no pop-ins are detected in the results this option is disabled (greyed-out).

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Options menu -> Show Pop-in List This option causes a pop-up window to appear which lists all recorded pop-ins. If no pop-ins are detected in the results this option is disabled (greyed-out). Options menu -> Ignore All Pop-ins This option causes the program to ignore any pop-ins that it has detected. This allows the user to force analysis to proceed without pop-ins in a case where their presence in the load/extension curve is disputed. If no pop-ins are detected in the results this option is disabled (greyed-out). Options menu -> Analyse for CTOD If it is not possible to calculate a valid KIc value the user may select the “CTOD” option to determine the value of critical crack tip opening displacement (CTOD). This feature is also available directly on the Graph Screen by clicking the “CTOD” button. Options menu -> Analyse for J If it is not possible to calculate a valid KIc value the user may select the “J” option to determine values of critical J fracture toughness. This feature is also available directly on the Graph Screen by clicking the “J” button. (Note that the “J” option is not available for straight notch compact specimens in accordance with BS 7448.) Options menu -> Why Not Valid ? If the program cannot derive a valid KIc value, the Options menu “Why Not Valid” feature will open a pop-up window listing the reason or reasons for the invalidity. This feature is also available directly on the Graph Screen by clicking the “?” button. References menu This is the same as the Main Screen menu bar. See section 4 for details.

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8.

APPENDIX - AN INTRODUCTION TO WINDOWS

All Phoenix Calibration & Services Ltd. applications programs are designed to run within the Windows environment on an IBM compatible personal computer. This instruction manual does not assume a working knowledge of Windows, however the user is urged to read the Windows documentation for complete information, as only the basic details are given here. For users new to the Windows environment the following is a glossary of important terms used:Mouse pointer - a pointing device on the screen which is moved using the mouse. Most operations within Windows are achieved by pointing to parts of the screen and pressing the buttons on the mouse. The shape of the mouse pointer will change as it points to different objects. The normal pointer is an arrow which points upwards and slightly left. When the pointer is placed in a text entry box it changes to an I-beam (similar to a capital I). When the computer is performing some action which requires it to suspend mouse operation temporarily (when reading or writing a file to disk for example), the pointer changes to an hour-glass. Click - the action of pressing the mouse buttons is usually known as “clicking”, not “pressing”, as it is a momentary press (click) which is usually used. The expressions “left click” or “right click” refer to clicking the left or right buttons on the mouse. Most operations use the left mouse button, so “click” usually means left click. Double-click - is to click the mouse button twice in quick succession. This is a specific action quite distinct from clicking the mouse button twice with an interval between. If the user has difficulty in clicking fast enough, the double-click response speed may be changed from within the Windows Control Panel. Please refer to your Windows manual. Edit cursor - also known as the Insertion Bar. Entering text or numerical values is often achieved by placing the mouse pointer over the box where the parameter appears, then selecting the value for editing by left clicking. This places an edit cursor at the point where the editing will take place. The edit cursor is in the form of a vertical flashing bar. The backspace and delete keys may be used while editing. Tabbing - instead of pointing and clicking on parameter entry boxes or buttons using the mouse, it is possible to use the tab key to make a selection. Tabbing selects the parameters in a repeating sequence, and using Shift+Tab reverses the sequence. The item which is selected is identified either by the presence of the edit cursor, or by a dotted box. If the selected item is a button it may then be operated by pressing the space bar on the keyboard. Regardless of the selection there is usually a button which has a bold outline. This is known as the Default Button and may be operated by using the ENTER key even when it is not currently selected. Greyed-out - when the operation of a button is inhibited for some reason its colour and outline are made grey. Clicking on a greyed-out button will not cause it to operate. Access keys - A title or label may have one character underlined. The keystroke Alt+character will select the parameter, for example to select a box titled “Mode”, press the M key while holding down the Alt key. Some types of data entry box contain a button with a downward pointing triangle (!). This may be operated by pressing Alt+down-arrow which

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will open a drop-down box of possible options for that parameter. The up and down arrow keys may then be used to highlight an option which is then selected by tabbing away from the box or pressing Alt+down-arrow again. Menu bar - at the top of the working window is a strip (bar) containing menu names. If the mouse is positioned on one of the menu names and the left button clicked, a drop-down menu appears. To select an option from a drop-down menu, click on the option. Alternatively, place the mouse pointer over the menu to select it, press the left mouse button and hold it down while pulling the mouse down to the required option. The option is selected when the mouse button is released. Short-cut keys - the menus on the menu bar also have underlined characters, but are not accessed using the “Alt+character” method. Instead, pressing F10 will select the menu bar, then the underlined short-cut keys or the left and right cursor keys may be used to select the required menu. Short-cut keys select and open a menu directly, the cursor key method requires the ENTER key to be pressed to open the selected menu. Once open, use the up or down cursor keys to make a selection (followed by ENTER), or just press an underlined short-cut key. To cancel the selection process press the escape key.

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Phoenix Calibration & Services Ltd Brick Kiln Street, Harts Hill, Brierley Hill, West Midlands, DY5 1JG, UNITED KINGDOM Tel. No. +44 (0)1384 480545 Fax No. +44 (0)1384 480602 E-mail: [email protected] Web site: http://www.phoenixcalibration.co.uk

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