ASTM. SACMA. Lamina/Laminate. Mechanical Tests. 0°/Warp tension. D3039 ...
Standard for high modulus carbon fiber composites (1980s). ➢ 0.5” gage length ...
Mechanical Testing of Composites
© 2003, P. Joyce
Tests Accepted by Mil-Hdbk-17 Test Category
Source of Test Method ASTM
SACMA
D2539, C613 D5300
RM 23, RM 24
Volatiles content
D3530
--
Resin flow
D3531
RM 22
Resin gel time
D3532
RM 19
Fiber areal weight
D3776
RM 23, RM 24
Moisture content
D4019
--
Tack
--
--
HPLC
--
RM 20
E1252, E168
--
D4065, D4473
RM 19
E1356
RM 25
Prepreg tests Resin content
IR DMA (RDS) DSC
© 2003, P. Joyce
Tests Accepted by Mil-Hdbk-17 Test Category
Source of Test Method ASTM
SACMA
D5229
RM 11
Fiber volume
D3171, D2734
RM 10
Resin content
D3171, D2734
RM 10
Void content
D2584
--
D792, D1505
--
--
RM 10
D4065
RM 18
--
RM 18
E831
--
D696, E228
--
Equilibrium moisture content
D5229
RM 11
Moisture diffusivity
D5229
--
Thermal diffusivity
E1461 © 2003, P. Joyce E1269
--
Lamina physical tests Moisture conditioning
Density Cured ply thickness Glass transition temperature (dry) Glass transition temperature (wet) CTE, out-of-plane CTE, in-plane
Specific heat
--
Tests Accepted by Mil-Hdbk-17 Test Category
Source of Test Method ASTM
SACMA
0°/Warp tension
D3039
RM 4, RM 9
90°/Fill tension
D3039, D5450
RM 4, RM 9
0°/Warp compression
D3410, D5467
RM 1, RM 6
90°/Fill compression
D3410, D5449
RM 1, RM 6
D3518, D5448, D5379
RM 7
Interlaminar shear
D5379
--
Short beam shear
D2344
RM 8
--
--
draft
RM 5
Lamina/Laminate Mechanical Tests
In-plane shear
Flexure Open-Hole Compression
© 2003, P. Joyce
Tests Accepted by Mil-Hdbk-17 Test Category
Source of Test Method ASTM
SACMA
Open-Hole Tension
D5766
RM 5
Single shear bearing
draft
--
Double-shear bearing
draft
--
Compression after impact
draft
M2
Mode I fracture toughness
D5528
--
Mode II fracture toughness
draft
--
D3479
--
--
--
Lamina/Laminate Mechanical Tests (cont.)
Tension/tension fatigue Tension/compression fatigue
© 2003, P. Joyce
Laminate Testing ¾ ASTM D638 Tensile Properties of Plastics – dogbone specimen
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Laminate Testing ¾ ASTM D3039 Tensile Properties of PMC Materials ¾ Used for most aerospace composites
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Laminate Testing ¾ ASTM D695 Compressive Properties of Rigid Plastics (1942) ¾ Uses an untabbed, dogboned, flat specimen
© 2003, P. Joyce
Laminate Testing ¾ Modified D695 Compression Test Method ¾Uses a straight sided specimen ¾Tabbed for strength (gage length to short to instrument using strain gages) ¾Untabbed for modulus ¾No ASTM standard governing this method ¾Defined in Boeing Specification Support Standard (BSS 7260, 1982) and SACMA Recommended Test Method (SRM 1-88, 1988)
© 2003, P. Joyce
Laminate Testing ¾ Modified ASTM D695 - Mil-Hdbk-17 interprets this technique to be for 0° direction properties of unidirectional coupons, and 0° and 90° properties of fabric coupons only (and then only when unit cell size of weave or braid is small.)
© 2003, P. Joyce
Laminate Testing ¾ ASTM D3410 Compressive Properties of PMC Materials by Shear Loading ¾ Standard for high modulus carbon fiber composites (1980s) ¾ 0.5” gage length for strain gage sometimes buckles. ¾ Tab failure also problematic.
Celanese fixture © 2003, P. Joyce
Laminate Testing ¾ ASTM D3410 Compressive Properties of PMC Materials by Shear Loading ¾ Standard for high modulus carbon fiber composites (1980s) ¾ 0.5” gage length for strain gage sometimes buckles. ¾ Tab failure also problematic.
IITRI fixture © 2003, P. Joyce
Laminate Testing ¾ ASTM D6641 Compressive Properties using CLC Fixture (2001) ¾ Evolved out of WTF ELSS fixture ¾ Uses straight sided, untabbed specimen ¾ Not recommended for unidirectional composites
© 2003, P. Joyce
Laminate Testing ¾ ASTM D2344 Short-Beam Strength of PMC Materials ¾ Low cost QC test ¾ Material screening
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Laminate Testing ¾ ASTM D5379 Shear Properties of Composite Materials by the V Notched Beam Method (Iosipescu)
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Laminate Testing (Iosipescu method)
© 2003, P. Joyce
Laminate Testing ¾ ASTM D3518 In-plane Shear (IPS) ¾ Uses ±45° laminate to extract shear properties. ¾ Strictly a shear design allowable ¾ Not used for QC
© 2003, P. Joyce
Laminate Testing ¾ ASTM D790 Flexural Properties of Un-Reinforced and Reinforced Plastics
© 2003, P. Joyce
Laminate Testing ¾ASTM D6484 Open Hole Compressive Strength of PMC Laminates (1999) ¾After Boeing Specification Support Standard BSS 7260, also described in SACMA Recommended Method SRM 3-88.
© 2003, P. Joyce
Laminate Testing ¾ASTM D6742 Filled Hole Tensile/Compressive Strength w Ne Laminates (2002) of PMC
© 2003, P. Joyce
Laminate Testing ¾Creep testing ¾Creep is defined as the change in a property over time when subjected to a constant forcing function. ¾Creep should be considered if the end use ¾involves high stress in the matrix dominated direction ¾high temperature ¾or exposure to a harsh chemical environment © 2003, P. Joyce
Laminate Testing ¾Creep is especially important in composites with a thermoplastic matrix, particularly as TsÆTg ¾Creep is expected to be small in thermoset matrix composites, due to cross-linking. ¾Creep testing is not used to provide primary design data, rather designs should be checked for creep deformation. © 2003, P. Joyce
Testing Fabric-Reinforced “Textile” Composites ¾Refer to ASTM D 6856 Standard Guide for . . . ¾Discusses special testing considerations for textile composites.
© 2003, P. Joyce
Adhesives Testing ¾ ASTM D1002 Single Lap Shear is the most common & industry standard test for: ¾ QC in-process inspection to verify mixing, cure, and surface preparation. ¾ Screening for materials selection.
“five finger” Al specimens
© 2003, P. Joyce
Specimens machined from composite laminate
Adhesives Testing ¾ ASTM D3528 Double Lap Shear minimizes peel, results in higher, more consistent shear strength.
Type TypeABspecimen specimen © 2003, P. Joyce
Adhesives Testing ¾ ASTM D3165 Notched Lap Shear ¾ QC for large laminated assemblies (voids) ¾ Compatibility of different resin systems
© 2003, P. Joyce
Adhesives Testing ¾ ASTM D1780 Adhesive Creep ¾ Apply constant load and measure deflection of scribe marks.
© 2003, P. Joyce
Adhesives Testing ¾ ASTM D1876 Tee Peel ¾ Requires two flexible adherends (Al)
© 2003, P. Joyce
Adhesives Testing ¾ ASTM D3167 Floating Roller (Bell) Peel ¾ One rigid, one flexible adherend
© 2003, P. Joyce
Sandwich Testing ¾ ASTM C297 Flatwise Tensile Strength of Sandwich Constructions (used as workmanship verification, unless very reliable NDE being used.)
© 2003, P. Joyce
Sandwich Testing ¾ ASTM C393 “Long Beam” Flexure ¾ 4 point bending produces uniform bending moment in the center section. ¾ Specimen is sized to induce compression failure in upper skin, not core shear. ¾ Also demonstrates that skin to core strength is adequate to achieve designed facesheet compression stress.
Paste Photo Here
© 2003, P. Joyce
Sandwich Testing ¾ ASTM C393 Beam Flexure ¾ Performed in addition to FWT on co-cured sandwich if rigorous structural requirement. ¾ Accounts for any knockdown from wrinkling/dimpling. ¾ Usually yields lower strength & modulus than solid facesheet tension or compression test.
© 2003, P. Joyce
Sandwich Testing ¾ Mil-Std 401B Core Shear ¾ Used to verify core splice performance. ¾ Can also be used to compare different surface preparations. ¾ Standard configuration uses ¾ 0.062” Al facesheets ¾ 8.1 pcf Al core
© 2003, P. Joyce
Sandwich Testing ¾ ASTM D1781 Climbing Drum Peel ¾ Used for characterization of adhesives for Al facesheet construction ¾ Workmanship test
© 2003, P. Joyce
References ¾ ¾ ¾ ¾ ¾ ¾
Course Notes, Test Methods for Composite Materials, Adams, D. (1991) Mil-Hdbk-17 Composite Materials Handbook Mil-Hdbk-23A Structural Sandwich Composites Wyoming Test Fixtures, Product Catalog No. 106 (2000) ASTM Annual Book of Standards (2001) Engineering Mechanics of Composite Materials, Daniel, I.M. and Ishai, O. (1994)
© 2003, P. Joyce