Compression, Bending, Torsion and Multiaxial Testing

In this chapter we consider the compression, bending, torsion and multiaxial testingMultiaxial testing of materials. Compression is a fundamental test as it is tension. The initial portions of stress–strain curves in compression for most materials have the same characteristics as in tension. Various material properties such as modulus of elasticityModulus of elasticity, elastic and proportional limitProportional limit, yield stressYield stress may be defined from the initial portion of the stress–strain curve in compressionStress-strain curve in compression. Many materials, even though they have the same elastic behavior in tension and in compression, their post-yield and failure characteristics in compression are quite different than in tension. We present the specimen types and the stress–strain curves in compression, and we compare the material behavior in compression to that in tension. Also, we present the bendingBending testing and torsion testsTorsion testing and a series of tests for the multiaxial characterization of materials. They include biaxial tension testsBiaxial tension test, biaxial tension/compression strip tests, tube testsTube test, spherical vessel testsSpherical vessel test, combined tension/compression–torsion ring tests, combined tension/compression–torsion tube tests, combined tension/compression–torsion–internal pressure tube tests. Finally, we present failure envelopes under multiaxial loading for isotropic, anisotropic and uneven materialsUneven materials.