Impact and flexure tests on hampfibre Essay Example | Topics and Well Written Essays - 1000 words

Impact and flexure tests on hampfibre - Essay Example Before analyzing the given data, we must have a look at the basic preliminaries and definitions about the deformation, impact velocity, Hooke’s law and others, Deformation Deformation is the study in continuum mechanics which defines the transformation of an object (material) from its original (reference) shape to a newly adapted form. Deformation can be caused by the external stress (force) effects such as electromagnetic force, gravity, stress, strain and load or temperature. Impact velocity It is the relative measure of the velocity of one object to another in a very small transient time before the interaction of the two objects (interaction could be the result of applied force). In ideal scenario the velocity of the impacting object must not be reduced to 0 and it rarely happens in practical situations. velocity_(impact) = (m_1\vec v_(1f) + m2 vec v_(2f))/m_1 ~ Vec_v shows the velocity vector*. Hooke’s law Hooke’s law is a concept of classical mechanics which discusses the force needed to compress or extend the shape by an amount X (distance). Hooke’s law is also a measure of the deformation of solid bodies as long as deformation impact is small. It is also defined as the first order linear approximation or the material response studied in material science and material engineering (Bansal, 2010). Plastic region: Area under the stress-strain graph after bypassing which, the permanent change and deformation in a material starts occurring. This plastic region is shown in the stress strain graph as the highest point in the curve. Before plastic limit, there is an elastic limit under which the material does not deform itself but it remained confined in the actuality of its originality. However as soon as the elastic and the plastic limit is breached Plastic deformation take place in this deformation, upon uplifting the force and the load, the material does not regain its shape but it tends to adapt the newly deformed shape as the cons equence of the load applied to bring about the change of the shape. Stress: Any force applied in purpose to change the shape and objet and to make that object slide against its own structure. \Shear Stress: It is the force which attempts to deform an object by applying pressure on the surface of the object. Sress = Force/Area (i.e. force per unit area) Stress is not a vector. It is a tensor. Elastic Deformation: region in the stress-strain graph where the deformation take place in a transient mode. It means that the deformation in this region is temporary. Beyond this limit, the material experiences plastic deformation which is permanent. Figure #1 The above figure shows the effect of the impact velocity on the three shapes and different samples. The above figure shows that the impact velocity of the 30 degree conical and the 90 degree conical shape is nearly the same because of having a harmony in the shape (as both are conical). The next shape which is a hemispherical shape, the f igure shows that it has less impact of the relative impact velocity as compared to the rest of the figures. Because the hemisphere has a changed shape and surface as compared to the conical tip, it exhibits an elasto-plastic dynamic behavior under examination. This also relates with the hemispherical heavenly bodies and other cosmological objects who while colliding with each other do not cause any explosion or sudden disruption, but are slowly deformed resulting catastrophic vibration (seismic) activities. Figure # 2 This diagram shows the effect of the load variation and its results on the various samples of three different shapes. With the varying samples of these conical 30, conical 90 and hemispheres shapes the load is also being shown to be varying and gradually rising under the scenario of the change of the shapes. This shows that as the shapes change the ability to deform an object or bypassing its deforming threshold and the requirement of the force to perform this task var ies in accordance with the