Predicting joint sealant performance of elastomers by computer simulation. I. Justification of method

Abstract

AbstractA computerized method has been developed for the analysis of the behavior of a sealed joint. The method is based upon the use of fundamental time‐dependent mechanical properties of a polymeric sealant, which can be easily determined in the laboratory, to feed a digital computer program that performs internal force balances within a given joint seal configuration by dividing the joint seal into a large number of “finite elements” in which the sealant properties are invariant. The computational method is an outgrowth of stress analysis programs that have been developed for use in the study of stress distributions within solid rocket propellant “grains.” Output from the computer program consists of a prediction of the overall geometric deformation of the sealant and the distribution of stresses and strains within the joint seal. Essential to the ideologic development of this method is the “separability” of time‐dependent and strain‐dependent aspects of the behavior of the material properties. However, the method should be operable even when this “separability” is only approximately maintained, as in many real materials. Fundamental properties have been determined on several typical sealant materials. A description is given of the mode of operation of the computational method, but detailed results are given in a companion article.