Effect of weld modelling on crashworthiness optimization

Design of ship structures that can absorb more energy during accidental loading scenarios without rupture contribute to the safety at sea. Therefore, innovative structural solutions have been sought for and implemented in practice, which have better crashworthiness properties compared with traditional stiffened panels. The enhanced characteristics are achieved through structural topology changes that lead to better energy absorption characteristics. To find the topologies with the best characteristics, optimization algorithms are commonly used. In this paper, we explore how these “best” designs are affected by the assumption made in modelling the structural joints such as welds and heat-affected zone. Web-core steel sandwich panels are optimized for maximum Energy per Mass (E/M) ratio until fixed penetration depth. Two alternative modelling techniques are compared, one where welds are considered and the other without welds. The differences in response and resulting best designs are discussed and presented.