Methods of analysis for constant loading and temperature conditions

At some stage, any design procedure will require assessments of the likely reliability of components. The criteria for judging reliability will certainly require an adequate knowledge of the stresses and strains resulting from the loading and environmental factors involved in the duty required of the component. These stresses and strains are used to make further assessments of, for example, the strength and deformations of the components and in turn these quantities can then be used in the material selection process for the component design. Obviously, such a process is iterative because there will also be trade-offs between the several requirements for adequate strength, manufacturability and of course cost, in seeking optimum solutions; each partner involved in the design process will claim to be most important. The owner however wants highest reliability, best performance and lowest cost. The manufacturer will claim he plays the most important role, because if the component cannot be made, it cannot perform. At the end of the day though, even if the component is well made and it performs to specification, nobody will be satisfied if after a short time and repeatedly thereafter, it falls to pieces. Design for strength is therefore of paramount importance to the owner and the operator of plant. By ‘strength’ should be perceived a suitable resistance to instability of any sort which leads to failure; examples are breakup of the material or excessive deformation.