CRASHWORTHINESS OPTIMIZATION OF NESTED AND CONCENTRIC CIRCULAR TUBES USING RESPONSE SURFACE METHODOLOGY AND GENETIC ALGORITHM

Abstract

IN THIS STUDY CRASHWORTHINESS OPTIMIZATION OF NESTED AND CONCENTRIC CIRCULAR TUBES UNDER IMPACT LOADING IS PERFORMED BY COUPLING FINITE ELEMENT MODEL, RESPONSE SURFACE MODELS AND GENETIC ALGORITHM. SPECIFIC ENERGY ABSORPTION (SEA) AND CRASH FORCE EFFICIENCY (CFE) ARE USED IN CRASHWORTHINESS OPTIMIZATION BECAUSE THESE CRITERIA ARE IMPORTANT INDICATORS FOR EVALUATING CRASHWORTHINESS PERFORMANCE. LENGTH AND THICKNESS OF THREE CONCENTRIC TUBES AS WELL AS RADIUS OF ONE TUBE ARE ADOPTED AS DESIGN VARIABLES BECAUSE THESE PARAMETERS ARE CONSIDERED EFFECTIVE ON SEA AND CFE. SEA AND CFE ARE CALCULATED USING EXPLICIT FINITE ELEMENT ANALYSIS. TO REDUCE THE COMPUTATIONAL COST OF THE OPTIMIZATION PROCEDURE, SIMPLE AND COMPUTATIONALLY CHEAP RESPONSE SURFACE MODELS FOR SEA AND CFE ARE CREATED TO REPLACE FINITE ELEMENT ANALYSES IN FURTHER CALCULATIONS. OPTIMIZATION RESULTS ARE PRESENTED FOR DIFFERENT WEIGHT FUNCTIONS THAT INDICATE RELATIVE IMPORTANCE OF MULTI-OBJECTIVE FUNCTIONS. OPTIMIZATION RESULTS CORRESPOND TO HIGH WEIGHT FACTORS FOR CFE LEAD TO OPTIMUM DESIGNS THAT DO NOT VIOLATE CONSTRAINTS. THESE DESIGNS CAN BE ADOPTED FOR USE IN PRACTICE.