ACCURATE REPRESENTATION OF LOCAL-EFFECTS DUE TO CONCENTRATED AND DISCONTINUOUS LOADS IN HYBRID-TREFFTZ PLATE-BENDING ELEMENTS

As opposed to conventional conforming elements, the assumed displaceme nt field of a hybrid-Trefftz (HT) element must accurately satisfy the differential equilibrium conditions while the conformity is then impos ed in a weighted residual sense. Unlike the homogeneous part of the el ement displacement field, the particular load-dependent part may be re presented, in the case of a concentrated or a discontinuous load, by a suitable local solution extending either over the whole plate or conf ined to a patch of elements in the vicinity of the load. The main adva ntage of such an approach is that the FE mesh and, to a large extent, also the solution accuracy are independent of the load. The paper pres ents explicit expression of local solutions for a line load and a patc h load which are of particular interest to plate bending analysis in t he engineering practice. The accuracy and efficiency of the approach a re assessed in a series of benchmark problems.