Evaluation of crack growth behaviour on sandwich metal panel using 2k factorial method

This study investigates the crack growth response on sandwich metal panel (SMP) combination of high strength steel (HSS) as faces and magnesium alloy (AZ31B) as core on the light armoured vehicles LAV. Currently, LAV uses a special solid steel which content heavy material that causes the LAV reduce its lifespan performance and limit the movement after shot by ammunition bullets with high impact until the crack starts to form. The main objective of this research is to develop SMP that can provide improvement in terms of life durability compared to existing materials in LAV applications. A crack growth test was done using compact tension, CT by comparing the improvement solid HSS and AZ31B with sandwich metal panel in terms of life durability and energy absorption. Crack growth response investigation focuses on the frequency, f = 10 Hz and stress ratio, R = 0.1 as control variables. Next, the Design of Experiment of the 2k factorial method was implemented by applying frequency, f (5 Hz and 10 Hz) and stress ratio, R (0.1 and 0.5) as statistical analysis. Twelve runs were carried out for the sandwich metal panel to obtain an optimum response for the number of life cycles and crack length in the empirical model equation and the best optimal D efficiency obtained. The increment of life cycle on crack growth analysis between HSS and SMP was about 18%, while the life cycle for AZ31B and SMP was about 34%. From the statistical result, an empirical model for the number of cycles has been chosen as optimum values for maximising the number of life durability on SMP at frequency, f = 10 Hz and stress ratio, R = 0.5. The increment of life cycle using optimum values between HSS and AZ31B with SMP was more than 60%. Thus, the potential of SMP to be replaced as an improvement in life durability for the light armour vehicle, LAV application has been verified.