Physical Testing Machine

Tensile Test

Tensile testing is one of the simplest and most widely used destructive mechanical testing method that subjects a material sample to uniaxial tension until failure. A machined specimen is placed in the testing machine and load is applied. An extensometer is used to measure elongation. The stress obtained at the highest applied force is the Tensile Strength. The Yield Strength is the stress at which a prescribed amount of plastic deformation is produced. Elongation describes the extent to which the specimen stretched before fracture. Information concerning the strength, stiffness, and ductility of a material can be obtained from a tensile test. Variations of the tensile testing include : room temperature, low and high temperature, shear tests, etc. Many performance parameters can be measured by tensile testing. The resulting data, a curve of force vs extension, shows the tensile profile of the test up to the point where the specimen breaks. Along this tensile profile there are many points of interest, chief among them the elastic limit and force to break or failure point.

Impact Test

In material science, resilience is the ability of a material to absorb energy when it is deformed elastically, and release that energy upon unloading. Proof resilience is defined as the maximum energy that can be absorbed up to the elastic limit, without creating a permanent distortion. The modulus of resilience is defined as the maximum energy that can be absorbed per unit volume without creating a permanent distortion. In the laboratories the resilience is calculated by the Charpy and Izod impact testing tests. The apparatus consists of a pendulum of known mass and length which is released from a known height to impact a notched specimen. The energy transferred to the material can be inferred by comparing the difference in the height of the hammer before and after the fracture (energy absorbed by the fracture event). The notch in the sample affects the results of the impact test, thus it is necessary for the notch to be of regular dimensions and geometry. The size of the sample can also affect results, since the dimensions determine whether or not the material is in plane strain.

Bending Test

The bending flexural test provides modulus of elasticity in bending values, flexural stress, flexural strain and the flexural stress-strain response of the material. The upper-positioned cylinder applies the bending force to specimen at preset angle. Then two oppsite horizontal cylinders bend the specimen to required angle. The common test requires machines which allow 180° bend test with complete sets of mandrels according to international standards.