Lap Shear Testing
Lap shear (tensile) testing is a method for testing adhesion by pulling bonded layers apart along the plane of adhesion. The result can be a clean breakaway of the adhesive layer from the substrate, or more likely a breakdown in the cohesion of either the substrate or the adhesive layer, or both. Applying tensile force accurately along the plane gives rise to configurations that minimise distortion away from the plane, including the use of spacers to take up the thickness of the substrate (dark blue) or adhesive layer (light blue):
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| Single lap shear |
Single lap shear (bevelled) |
Single lap shear (joggled) |
Double lap shear |
Double-butt lap shear |
Each end of the sample is held by vice grips and pulled apart at a controlled rate, and the force applied is expressed proportional to the total adhesive surface area, or shear area.
Related test types
Lap shear test standards
A very wide range of tensile lap shear standards have been developed by international and trade organisation. Commonly used test standards include:
- ASTM C273-11 : shear properties of sandwich core materials
- ASTM D906 : Strength Properties of Adhesives in Plywood Type Construction in Shear by Tension Loading
- ASTM D1002 : Apparent Shear Strength of Single-Lap-Joint Adhesively Bonded Metal Specimens by Tension Loading (Metal-to-Metal)
- ASTM D2339 : Strength Properties of Adhesives in Two-Ply Wood Construction in Shear by Tension Loading
- ASTM D2919-01 : Determining Durability of Adhesive Joints Stressed in Shear by Tension Loading
- ASTM D3163-01 : Determining Strength of Adhesively Bonded Rigid Plastic Lap-Shear Joints in Shear by Tension Loading
- ASTM D3164-03 : Strength Properties of Adhesively Bonded Plastic Lap-Shear Sandwich Joints in Shear by Tension Loading
- ASTM D3528-96 : Strength Properties of Double Lap Shear Adhesive Joints by Tension Loading
- ASTM D3846-08 : in plane shear strength of reinforced plastics
- ASTM D4680 -98 : Creep and Time to Failure of Adhesives in Static Shear by Compression Loading (Wood-to-Wood)
- ASTM D5169-98 : shear strength (dynamic method) of hook and loop touch fasteners
- ASTM D5868-01 : Lap Shear Adhesion for Fiber Reinforced Plastic (FRP) Bonding
- ASTM F521-83 : bond integrity of transparent laminates
- ASTM F2255-05 : strength properties of tissue adhesives in lap shear by tension loading
- ASTM F2258-05 : strength properties of tissue adhesive in tension
- ASTM F2458-05 : wound closure strength of tissue adhesives and sealants
- BS EN 2243-2 : Aerospace series. Non-metallic materials. Structural adhesives. Test method. Peel metal-metal
- BS EN 520 : Gypsum plasterboards. Definitions, requirements and test methods
- ISO 9664 : adhesives - test method for fatigue properties of structural adhesives in tensile shear
- ISO 10123 : adhesives - determination of shear strength of anaerobic adhesives using pin-and-collar specimens
- ISO 9311-2 : adhesives for thermoplastic piping systems - Part 2: determination of shear strength
- ISO 15109 : Adhesives - Determination of the time to rupture of bonded joints under static load
- ISO 15509 : Adhesives - Determination of the bond strength of engineering-plastic joints
- ISO 11003-2 : Adhesives - Determination of shear behaviour of structural adhesives - Part 2: Tensile test method using thick adherends
- SAE J 1523 : Metal to Metal Overlap Shear Strength Test for Automotive Type Adhesives
- SAE J 1525 : Lap Shear Test for Automotive Type Adhesives for Fiber reinforced plastic (FRP) Bonding
