Load distribution modelling for pin-jointed trusses by an inverse approach

The paper considers the load distribution modelling for pin-jointed trusses when an approximate value of the normal stress on a suitable number of elements is known. This inverse problem is formulated in the least square sense, directly relating the stress on the elements with the external loads, and successively solved using an iterative scheme which uses a standard decomposition method for the stiffness matrix and the conjugate direction strategy. In order to obtain a regularized solution of this problem, and so cut out the errors contained in the known term of the equation system, the generalized cross validation criterion is used in a form suitable for iterative methods. Some numerical results allow an analysis of the algorithm's performance.