Js. Pang et F. Tin-loi, A penalty interior point algorithm for a parameter identification problem in elastoplasticity, MECH STRUCT, 29(1), 2001, pp. 85-99
This paper deals with a special class of parameter identification problems
in structural plasticity. Specifically, we address the problem of identifyi
ng yield limits and hardening moduli from knowledge of the displacement res
ponse of the structure under a given set of proportional loads. Under the a
ssumptions of piece-wise linear holonomic (reversible) plasticity and a sui
tably discretized structure, the inverse problem can be formulated as a spe
cial optimization problem known as a Mathematical Program with Equilibrium
Constraints (MPEC), a key feature of which is the presence of complementari
ty conditions, involving the orthogonality of two sign-constrained vectors.
A recently developed numerical scheme, the Penalty Interior Point Algorith
m (PIPA), is proposed for solving the identification problem. Some computat
ional results for a hypothetical beam on elastoplastic springs are also giv
en.