Structural Appraisal with Optimization for Performance Evaluation Within Limit Criteria

Application of structural load produces stress, strain and deformation over period of load application, that reduces the strain energy (U) of structural system, and also the designed limits are critical factors beyond which performance becomes inadequate and unsafe for continuous load application, which make appraisal an integral aspect of structure’s life cycle and to avoid sudden failure or collapse. The study evaluated the significance of structural appraisal using optimization method to determine functionality, fitness and performance. Structures are designed with respect to engineering standards, codes and specifications, also by functionality can only tolerate negligible deformation and minimal displacement (ie W = F. δs =0, if δs → 0) for the expected limit state and stability. The paper further considered structural failure condition in terms of certain criteria including stress (ie, σ_p ≤ σ_a), strain (ε_p ≤ ε_a) and inelastic deformation, which are factors resulting from work-done to support the applied forces (loads), which consumes available strain energy of structural system leading to gradual reduction over period of time. Evaluation of these parameters using optimization technique provides information on the structural life (ie Strain energy less work done), indicating that strain energy reduces over period of time and as a function U_r = U_i - ∆W, where ∆W is reduction in strain energy over time period. A mathematical optimization is the selection of best solution with regard to some criterion from set of available alternatives (eg, F, σ, ε, E and t), that involve maximizing or minimizing a real function for overall benefit of the system. In conclusion, appraisal and engineering reliability are two important parameters with similar outcome and interpretation that defines characteristic performance requirement of engineering system, similarly the reliability function expresses the probability that an engineering system will function under stated conditions for specific time period which provide the assurance of performance.