PREDICTION OF ERROR IN FINITE-ELEMENT RESULTS

The precision in the results of analysis using the finite element (FE) technique requires that a structure to be analyzed shall be discretiz ed using a finer mesh. The number of elements into which the structure shall be discretized so as to obtain the FE results within an accepta ble tolerance is usually decided by experience or a guess. Moreover, t he error in the results of FE analysis is an unknown, therefore, it is difficult to say whether the results are within an acceptable toleran ce. It is due to these reasons that an extrapolation technique is pres ented in the present paper to predict the results more precisely by ca rrying out the analysis for two mesh configurations which have a diffe rent number of elements in each case, but possess a similar discretiza tion pattern. This is done by taking into consideration the variation of parameters within the body of the structure. The error in the resul ts of analysis of plane strain and plate bending problems has been fou nd to be inversely proportional to the number of elements. Two other a lgorithms for the modeling of error have also been tested. Several num erical examples under the two categories of problems considered in the study are presented to demonstrate the utility of the proposed extrap olation technique. Copyright (C) 1996 Elsevier Science Ltd.