Stress and stain :: essays research papers

  Ã‚  Ã‚  Ã‚  Ã‚  Simple Stress and Strain   Ã‚  Ã‚  Ã‚  Ã‚     Ã‚  Ã‚  Ã‚  Ã‚  The strength of materials are expressed from the point of view of machine designer. A machine designer needs to know the properties of different materials so that he can select the most suitable material for each part of a machine. A machine designer uses his information of stress to make sure that the stress is reasonable and that each part of the machine is sufficiently strong. Strength of materials is the scientific area of applied mechanics for the study of the strength of engineering materials and their mechanical behavior in general (such as stress, deformation, strain and stress-strain relations). Strength is considered in terms of compressive strength, tensile strength, and shear strength, namely the limit states of compressive stress, tensile stress and shear stress respectively.   Ã‚  Ã‚  Ã‚  Ã‚  One can see the importance of stress and strain. They are an indication of how severely the part in machine is loaded and how it is a factor that determines whether the forces applied are reasonable. Stress and strain always occur together. When a material is subjected to stress, it deforms, and when a material is deformed there must be strain. If the stress and strain are not the same for all materials, then it is found by experiments There is a relation between the stress and the strain for any given material. It said, when the relationship between the two are given, the stress and the strain can be found in one another. All materials deform when subjected to stress and it is necessary to be able to calculate the deformation of a body under load, because in most cases the deformation is more momentous than the stress.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Stress is in all probability the most imperative word in the subject matter of strength of materials. Stress is defined as force per unit area. It has the same units as pressure, and in fact pressure is one special variety of stress. However, stress is a much more complex quantity than pressure because it varies both with direction and with the surface it acts on. The simple stress are: compression (stress that acts to shorten an object), tension (stress that acts to lengthen an object), and shear (stress that acts parallel to a surface). Shear can cause one object to slide over another. It also tends to deform originally rectangular objects into parallelograms. The most general definition is that shear acts to change the angles in an object.