Compression test is just contradictory in nature to tensile test. Nature of deformation and fracture is fairly different from that in tensile test. Compressive load tends to squeeze the sample. Brittle materials are generally weak in tension but strong in compression. Hence this test is usually performed on cast iron, cement concrete etc. That’s why determine the ultimate compressive strength which is essential before using a material. This strength is evaluated by conduct of a compression test. But ductile materials like aluminium and mild steel which are sturdy in tension are also tested in compression.
The compression test can be performed on UTM by keeping the test-piece on base block and moving down the central grip to apply load. It can also be able to perform on a compression testing machine. A compression testing machine has two compression plates/heads. The upper head is movable while the lower head is stationary. One of the two heads is prepared with a hemispherical bearing to obtain. Uniform distribution of load over the test sample ends. A load monitor is fitted for display the applied load and elongation. The Shear strength test is also done by UTM. Shear strength is measured as the force/area sheared. It is essential in film and sheet products where failures from this type of load can occur, whereas for the design of molded and extruded products it is hardly a factor. Others include testing the material to determine its suitability for various test sample processes and whether its properties will meet the particular end-use application, as well as for quality control following development to ensure a lot of consistency. For more information visit- http://www.testing-
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