a b s t r a c tThis paper focuses on natural silk/epoxy composite square tubes energy absorption and failure response. The tested specimens were featured by a material combination of different lengths and same numbers of natural silk/epoxy composite layers in form of reinforced woven fabric in thermosetting epoxy resin. Tubes were compressed in INSTRON 5567 with a loading capacity of 30 kN. This research investigates the influence of the wall lengths on the compressive response and also failure mode of the tested tubes are analysed. The load-displacement behaviour of square tubes recorded during the test. Since natural woven silk has been used as textile in centuries but due to rare study of this fabric as reinforcement material for composites, the results of this paper can be considerable. Outcomes from this paper might be helpful to guide the design of crashworthy structures.

This paper describes an experimental evaluation of the crashworthiness characteristics of a novel design for cost-effective crashworthy composite glass fibre-reinforced plastic (GFRP) sandwich structures. All the samples are based on the concept of the ''double-layered" foamfilled block, i.e. two foam-core sheets which are wrapped by reinforcement woven fabric, that acts as the reinforcement face and meanwhile ties the core layers and faces together, thus preventing catastrophic failure under axial loading conditions. The design, manufacturing and crush testing of rectangular blocks fabricated are described. Special attention is focused on the analysis of the mechanics of the block axial collapse, emphasizing on the mechanisms related to the crash energy absorption during the compression of the composite blocks with and without use of two types collapse trigger mechanism. Experimental results indicated high crushing force efficiency was achieved up to 80%.