In structural analysis and design, it is essential to define the material properties associated with the targeted structural systems. When harsh environmental or operational conditions are of primary concern, the mechanical properties of materials must be quantified by considering the effects of the conditions. The aim of this study is to develop a new test database on the mechanical properties of materials for marine applications, such as mild steel, high-tensile steel, aluminium alloy 5083-O and stainless steel 304L, focusing on the effects of cold temperatures and strain rates. Discussion of the new test database refers to extant test databases where available. Moreover, test coefficients that may be useful in the existing constitutive equations for the materials are suggested and the details of the test database are documented.

Ship–ship collisions continue to occur regardless of efforts to prevent them. The collisions involve highly nonlinear characteristics associated with structural crashworthiness, including crushing and fracture as well as buckling and plastic collapse. When applying nonlinear finite element analysis (NLFEA) to solve these problems, a reliable critical fracture strain accounting for strain-rate effects due to collision speed must be implemented. This study proposes a practical method to estimate the dynamic fracture strain to be used for the structural crashworthiness analysis associated with the collisions. For this purpose, the strain-rate characteristics in struck ship were investigated by NLFEA, in which the striking vessel was assigned various velocities in the range of practical ship speeds. Based on computations, an empirical formula was developed to calculate the strain rate at a given collision speed, allowing for a practical estimation of the dynamic fracture strain. The formula is validated by a comparison with experiment.

Pinned electrodes of the magnetic tunnel junction (MTJ) consisting of $\mathrm{Ta}/{\mathrm{AlO}}_x/\mathrm{CoFe}\mathrm{(x)/}\mathrm{IrMn}/\mathrm{NiFe}/\mathrm{Ta},$ where $\text{35\hspace{0.05em}Å<x<87.5\hspace{0.05em}Å,}$ were thermally annealed and analyzed using Auger electron spectroscopy and transmission electron microscopy in order to study the effects of the CoFe thickness on the interdiffusion of elements in the pinned electrode. Increasing CoFe thickness reduced the Mn migration out of the IrMn layer towards the tunnel barrier. An $\text{87.5−Å−}\mathrm{thick}$ CoFe layer completely blocked the Mn diffusion up to 350 °C with minimal reduction of the tunneling magnetoresistance (TMR) ratio when full junction was fabricated. Although other mechanisms could be responsible for the thermal degradation of the MTJ, the Mn diffusion appears to be related to the reduction of the TMR at 300 °C. Since the presence of Mn in the tunnel barrier as an impurity is detrimental to the junction performance, reduction of Mn migration towards the tunnel barrier by increasing the CoFe electrode should improve the postannealed performance of the junction.