A note on integration schemes for the microplane model of the mechanical behaviour of concrete

This paper discusses some aspects of the practical implementation of the very comprehensive ‘microplane’ model of the mechanical behaviour of concrete, proposed by Bažant and coworkers. This implementation involves numerical integration of some quantities over a hemisphere. The solution usually adopted is Gaussian integration with 21 or 28 points. However, Qiu and Crouch recently showed that this may be insufficient, and proposed to use more Gauss points. However, numerical experience shows that this strategy is relatively inefficient. Also, generating Gaussian integration schemes of high order on a hemisphere is a cumbersome task. An alternative integration scheme is proposed, which combines numerical efficiency and ease of automatic generation of more and more refined integration formulae. Copyright © 2004 John Wiley & Sons, Ltd.