Effect of triggering on the axial crushing behavior of GFRP tubes: Experimental investigation and optimization

Composite thin-walled tubes made of glass fiber reinforced plastics (GFRP) are attracting great attention due to their lightweight and outstanding crashworthiness capacity. Implementing triggers to the design of GFRP composite tubes enables a further increase in specific energy absorption while simultaneously reducing peak crushing force. Motivated by these facts, a notch-type triggering mechanism is suggested in this work to enhance the energy absorption capabilities of circular GFRP composite tubes. GFRP tube samples with (0(degrees)/90(degrees))8 layups are manufactured using the roll wrapping process. Subsequently, these samples are triggered and subjected to quasi-static axial compression tests. The diameter, quantity and placement of the triggering notches are selected as design parameters, and experiments are carried out using Taguchi's L9 orthogonal array. Each of these parameters has three levels to identify the optimal combination of design parameters. To optimize multiple responses, the weighted aggregated sum product assessment, a multiple criteria decision-making technique, is employed in conjunction with mono-criteria optimization. The findings indicated that substantial enhancements can be realized in all parameters related to energy absorption performance by triggering progressive crushing modes in a controlled manner using a notch-type triggering mechanism. In particular, the findings indicated that the specific energy absorption and the crush force efficiency of the intact GFRP composite tubes could be improved up to 18% and 68.3%, respectively, by the selection of appropriate triggering parameters.