Identification of elastodynamics load using drbem and dynamic programming filter

Abstract

This chapter reviews the first coupling application of the dual reciprocity boundary element method (BEM) (DRBEM) and dynamic programming filter to inverse elastodynamic problem. The DRBEM is the only BEM method that does not require domain discretization for general linear and nonlinear dynamic problems. As the size of numerical discretization system has a great effect on the computing effort of recursive or iterative calculations of inverse analysis, the intrinsic boundary-only merit of the DRBEM causes a considerable computational saving. On the other hand, the strengths of the dynamic programming filter lie in its mathematical simplicity, easy to program and great flexibility in the type, number and locations of measurements and unknown inputs. The combination of these two techniques is therefore very attractive for the solution of practical inverse problems. In this chapter, dynamic load is estimated based on noisy measurements of velocity and displacement at very few locations. Numerical experiments involved with the periodic and Heaviside impact load are conducted to demonstrate the applicability, efficiency and simplicity of this strategy. The chapter also investigates the affect of noise level, regularization parameter, and measurement types on the estimation.