A combined experimental study and numerical simulation is performed to investigate the effect of core materials on low-velocity impact behaviour of sandwich panels. Dynamic responses of three types of corrugated sandwich panels with the same geometric configurations, which consist of the same CFRP (carbon fibre-reinforced plastic) face sheets, but the different corrugated cores including aluminium alloy, stainless steel and CFRP are investigated in the present research. Reasonably good agreement has been achieved by comparing impact force, energy absorption and failure modes between experimental results and numerical simulation predictions. The present research reveals that fracture stress and fracture strain of the core material have a significant influence on the performances of the sandwich panels under low-velocity local impact, sandwich panels with stainless steel core has the largest capability of load carrying and energy absorption. Conclusions presented in the present research would be used in the development of neoteric lightweight multifunctional smart structures.

Experimental investigations on the mechanical responses of fully clamped circular plates with prefabricated crack at room temperature and low temperature have been conducted. Initial cracks with different lengths were prefabricated by the electrical discharge machining method. Low ambient temperature was created by the liquid nitrogen in a low-temperature chamber, and a dropping hammer was dropped from the same height with a constant impact energy of 5 J to carry out the repeated impact. Experimental test results show that the prefabricated crack has a significant influence on the mechanical behavior of the thin plates. The maximum impact force decreases with increase of the crack length, and the threshold impact number until fracture decreases with increase of the crack length. It is also observed from the test results that the maximum impact force increases with decrease of the temperature, while threshold impact number until fracture and the plastic permanent deformation decreases due to the brittleness of the material in low temperature. The present investigations provide useful insight into the failure mechanism of the clamped thin plate with initial crack under low-velocity repeated impacts in low temperature, which will lead to a guideline for research and design of marine structures in the arctic area.

Deck structures subjected to drop-weight low-velocity impact are critical safety elements for ships and offshore structures. Therefore, the aim of the present study is to propose experimental research on dynamic responses of deck structures composed of stiffened plates subjected to drop-weight impact of a wedge impactor. The first step was to fabricate a conventional stiffened plate specimen and a strengthened stiffened plate specimen, as well as a drop-weight impact tower. Then, drop-weight impact tests were carried out. Test results show that local deformation and fracture occurred in the impact area. A sharp wedge impactor caused premature fracture, even under relative low impact energy; the permanent lateral deformation of the stiffened plate was reduced by 20–26% by the strengthening effect of a strengthening stiffer; residual stress and the stress concentration of the cross-joint caused by welding may cause undesired brittle fracture. The present investigation provides useful insight for improving the crashworthiness design of the deck structure of ships and offshore structures.