Materials Assignment Example | Topics and Well Written Essays - 2500 words

Materials - Assignment Example Storage tanks and other structures operating in a corrosive environment would prefer the use of stainless steel material of density 8200kg/m^3. ((Bansal R.K, 1998) Measurement of densities is critical since a defective product with a cracks or porosity would indicate a different density. Determination of density of a component indirectly leads to the calculation of the total weight of the structure and the corresponding stress due to this self weight. 2. Stress and Strain- Stress is defined as the intensity of force or force per unit area. In an engineering design the maximum allowable stress for a particular material is predefined and is a function of its yield strength. Therefore when a member has stresses beyond the allowable range, the area resisting this force is increased to bring it within the allowable range. Strain is defined as defined as the elongation of a structure per unit length. Calculating the strain helps the design engineer in comparing the values with the maximum allowable deflection.( Timoshenko Stephen and Gere James, 2004) 3. Tensile and Compressive strength- When a force is applied on bar or a structure in such a manner that it forces it to elongate, the resulting stresses are tensile stress. The maximum value of this particular stress for a particular material is called Tensile strength. ... The behaviour of the material is linear till this point. (b) The strain increases rapidly and the material shows elastic behaviour up to the elastic limit. (c) Beyond this point a significant increase in strain has only a minor change in tensile force. The material at this point is yielding and the point at which this starts is called the yield point. (d) Beyond the yield point to the lower yield point the material show plastic behaviour with large change in strain showing no change or a partial dip in stress values. The material is thus encountering plastic deformation.( Timoshenko Stephen and Gere James, 2004) 5. Modulus of Elasticity- As discussed in the previous graph stress is directly proportional to strain up to the proportional limit i.e Stress ? Strain or Stress= E x Strain. E here represents the Modulus of Elasticity and is dependent on the nature of the material. The elongation for a bar of length L, cross sectional area A under the impact of a force P having modulus of el asticity as E is given by ?L= P*L/(A*E). Modulus of elasticity is therefore critical in evaluating deflections. ( Timoshenko Stephen and Gere James, 2004) Experiment using Round piece of mild steel ( Timoshenko Stephen and Gere James, 2004) Reading Load Extension Strain Stress 1 50 0.09 0.00046 0.10186 2 100 0.19 0.00097 0.20372 3 150 0.29 0.00149 0.30558 4 160 0.34 0.00174 0.32595 5 165 0.46 0.00236 0.33614 6 170 0.78 0.004 0.34632 7 180 0.84 0.00431 0.36669 8 190 0.91 0.00467 0.38706 9 200 0.98 0.00503 0.40744 10 210 1.07 0.00549 0.42781 11 220 1.24 0.00636 0.44818 12 230 1.49 0.00764 0.46855 13 240 1.88 0.00964 0.48892 14 250 2.39 0.01226 0.5093 15 255 3.95