ASTM D2105
Tensile Grips for Fiberglass Pipe and Tube
ASTM D2105 Tensile Grip – Universal Grip Data Sheet (PDF)
ASTM D2105 is the standard test method for longitudinal tensile properties of fiberglass pipe and tube, covering glass-fiber-reinforced thermosetting-resin pipe (RTRP) and glass-fiber-reinforced polymer mortar pipe (RPMP). The specimen is a full section of the pipe itself, loaded along its axis until it breaks. The hard part of the test is not the pulling but the holding: a composite pipe end crushes or splits in ordinary jaws long before the wall reaches its tensile strength. Universal Grip builds D2105 tensile grips that clamp the pipe around its full circumference over internal support plugs, so the load goes into the wall evenly and the failure happens in the gage section where it belongs.
What ASTM D2105 Measures
The method reports the comparative longitudinal tensile properties of the pipe as a product, not of the laminate as a coupon: modulus of elasticity, yield stress where a yield point occurs, elongation beyond yield, tensile strength, elongation at break and energy absorption, all under defined conditions of pretreatment, temperature and testing-machine speed. Because filament-wound and centrifugally cast pipe have properties that depend on the winding angle and the wall construction, testing the whole section captures what a flat coupon cannot. The standard is generally limited to pipe 6 in. (150 mm) in diameter or smaller, with larger sizes allowed where the apparatus exists. ASTM notes the data support research, design, quality control and specification acceptance, but that creep, fatigue and impact tests are better suited to loads that differ widely from the test's load-time scale.
How the ASTM D2105 Test Works
Cut a full-section specimen from the pipe or tube and measure its outside diameter and wall thickness per ASTM D3567 so the cross-sectional area can be calculated.
Condition the specimen per ASTM D618 and record the pretreatment and temperature, which the standard treats as part of the test definition.
Fit the internal support plugs into each end of the pipe so the wall is backed up when the jaws close.
Close the circumferential grips on each end, keeping the pipe axis on the load line of the testing machine.
Attach an extensometer that meets ASTM E83 to the gage section if modulus or elongation is required.
Load in tension at the speed specified by the standard until the pipe breaks, and record force and extension throughout.
Calculate tensile strength from the maximum force and the measured wall area, with modulus, yield and elongation taken from the curve.
Specimens and Setup
Specimens are full sections of pipe or tube; the gage section must be free of the grip zone so that end effects do not control the result.
Specimen length, the number of specimens and the crosshead speed are set by the current edition of D2105 — confirm them against your copy before you cut material.
Internal plugs should match the pipe bore closely: too loose and the wall still crushes, too tight and the plug pre-stresses the end.
Use a load frame that meets ASTM E4, with enough daylight for the pipe length plus two grip assemblies.
Record pipe construction (winding angle, liner, resin) with the results, since the method is comparative between products.
Universal Grip ASTM D2105 Fixture
Circumferential grip faces distribute load around the pipe wall
Internal support plugs prevent crushing of the pipe ends
Self-aligning design keeps load on the pipe axis
Serrated circumferential jaws in hardened alloy steel
Grip sets sized to your pipe or tube outside diameter and wall
Load capacity sized to the pipe; 100 kN typical, higher on request
Clevis pin or threaded adapters to suit electromechanical and servo-hydraulic frames
Applications
Fiberglass (GRP/FRP) pipe and fittings
Composite tube and drive shafts
Piping system design data
Pipe production QC and specification acceptance
Related Standards and Products
Send us your specimen dimensions, required capacity and machine connection through our contact page and we will quote an ASTM D2105 pipe tensile grip set. Request a quote
ASTM D2105 FAQ
What pipe sizes does ASTM D2105 cover?
The method is generally limited to pipe 6 in. (150 mm) in diameter or smaller. Larger pipe may be tested where the grips and load frame can handle it, and we build grip sets to order for larger diameters.
Why not cut flat coupons from the pipe wall?
D2105 is written for the full pipe section because the longitudinal properties of a filament-wound or cast wall depend on the complete construction. Cutting a flat coupon changes the fiber path and the result; coupon methods such as ASTM D3039 are for flat laminates.
What stops the pipe end from crushing in the grips?
Internal support plugs sized to the bore back up the wall while the circumferential jaws close around the outside. The load is carried by friction and serration over the full perimeter rather than at two flat jaw faces.
Which properties come out of the test?
Tensile strength, modulus of elasticity, yield stress where a yield point exists, elongation beyond yield, elongation at break and energy absorption. Modulus and elongation need an extensometer on the gage section.