Introduction In engineering, materials are exposed to different types of loads. The loads that materials can be subjected to can be listed as tensile, compression, bending, shearing, or twisting. At the same time, these loads can differ statically or dynamically. The material may have to resist one or more of these loads at the same time. In this case, it is necessary to know which material to use under which conditions. In order to group materials, their reactions under certain loads are observed with tests, and the mechanical properties of the materials are thus revealed. Mechanical characterization of materials at small length scales – Maria F. Pantano, Horacio D. Espinosa and Leonardo Pagnotta We can separate the tests for obtaining elasticity properties into static and dynamic. For a test to be static, the force must be applied at a maximum frequency of 1 Hz, at a constant and one time only. In this case, the stress is constant and the elongation ratio is less than 0.25 in the static test. Dynamic tests are used for these types of loads since static tests cannot form an adequate model for suddenly changing loads. In dynamic testing, the load is variable and a sinusoidal deformation is applied to the sample. These tests can also be performed at high or low temperatures. As a result of dynamic tests, hardness and damping information are obtained. We can examine fatigue tests as a sub-branch of dynamic tests. The load is applied cyclically. These tests are performed with tensile-pull, compression-compression, or compression-reverse tensile cycles. As a result of the fatigue test, the life of the materials can be determined. Fatigue strength and cracking resistance are also determined with the fatigue test. Tensile Test Tensile testing is one of the most common tests in engineering to determine the strength properties of materials. It is done to determine the mechanical properties of isotropic materials. This test is basically based on the application of a tensile force on the specimen from opposite faces in the same direction, and monitoring the stress on the material until the material breaks. As a result of the tensile test, yield strength, maximum tensile strength, ductility, Young’s modulus, shear modulus and Poisson’s ratio of the material can be obtained. Stress – Strain Curves Stress and Strain Curves The nominal tensile stress applied to the material during testing is as follows: Where F is the tensile force and the A_0 is the cross-sectional area under tension. And the strain is defined as; Where L_0 is the initial length of the speciemen and Δ_L  is the elongation of the material after the test. With the values derived from the test, the stress-strain curve is obtained. This curve reveals the material’s breaking point, yield strength, maximum tensile strength, and brittleness-ductility condition. Another benefit is that it gives information regardless of the material’s dimensions. J. R. Davis – Tensile Testing (2004) The diagram above shows the stress-strain curve of a brittle material. For most curves, the initial part is linear. The yield strength value is obtained on the curve when a curve parallel to the slope of the curve is drawn from the point where the elongation in the stress-strain curve is 0.2%. We can determine the maximum stress a material can withstand without permanent damage using its yield strength. Up to this point, the object is in the elastic region. After this, the material enters the plastic area, where the forces placed on it cause permanent damage. Yield Stress The slope of the imaginary line we draw to find the yield strength gives us the Young’s modulus, which is an important material property. Young’s modulus is obtained by: The following equation represents Poisson’s ratio, which is the negative of the ratio of horizontal displacement to vertical displacement: Test Most of the cross-sectional views of the specimens used in the tensile test are shown in the figure. Samples can be formed as a sheet or a cylinder. Different clamping types may be used depending on various materials and measurement sensitivity levels. Each method of binding has advantages and disadvantages of its own. Springer Handbook of Materials Measurement Methods-Springer (2006)  Tensile tests are carried out according to certain standards. The standards also differ according to the type of material. For example, tensile tests of plastic materials are performed according to the ISO 527-1 standard. For metallic material tests at room temperature, the ISO 6892-1 standard is used. Apart from these, some of the other standards for tensile tests are: ISO 6259-1 – Thermoplastics Pipes – Determination Of Tensile Properties ASTM D 638 – Tensile Test for Plastics ISO 4136 -Destructive tests on welds in metallic materials — Transverse tensile test TS ISO 37, ASTM D 412, DIN 53504 – Standard Test Methods For Vulcanized Rubber And Thermoplastic Elastomers-Tension ISO 6892-2 – Metallic Materials – Tensile Testing – Part 2: Method Of Test At Elevated Temperature Compression Test The compression test demonstrates how materials behave when compressed or crushed. The test typically lasts until the substance breaks down or until a predetermined limit. The load that the material can withstand before tearing and the extent of its degradation up to this point are thus calculated. In order to test a material, it is often heated or cooled and subjected to many directions of compressive force. However, tests can be performed under varied settings. Materials with high tensile strength generally have low compressive strength. For this reason, these materials are examined by compression testing. The materials on which the most compression tests are performed are generally brittle materials, for example, composites, concrete, wood, metal, and brick materials; polymers, plastics, and foams. A force-strain curve is obtained as a result of the compression test. The force is then converted to stress to create a stress-strain curve. This curve is very similar to the stress-strain curve in the tensile test. Only the axes are in the direction to show the shortening. Compression Stress – % Compression Deformation The calculations in the tensile test are