Compression Testing

When compression testing of material or product is performed, the test item is squeezed or compressed by aligned opposing loads or forces. Such tests characterize material performance under constant strain or stress conditions fall into the category of creep and stress relaxation. Depending on the material type, compressive properties can be dramatically different than tensile properties. Compression tests can be performed on static or dynamic systems. Static systems are usually the system of choice due to the larger displacement offered, and the relatively slow speed of the system for safety purposes. The most common fixture for compression testing is the compression platen. Ideally, a set of compression platens will provide parallel surfaces for loading of the specimen. They also should be of sufficient hardness and smoothness as not to influence the specimen results. Platens are available in two types, fixed and spherical seats. The spherical units provide for automatic alignment for higher modules materials, or specimens that have loading surfaces that are not parallel.