The hinge of bivalve shells can sustain hundreds of thousands of repeating opening-and-closing valve motions throughout their lifetime. We studied the hierarchical design of the mineralized tissue in the hinge of the bivalve Cristaria plicata , which endows the tissue with deformability and fatigue resistance and consequently underlies the repeating motion capability. This folding fan–shaped tissue consists of radially aligned, brittle aragonite nanowires embedded in a resilient matrix and can translate external radial loads to circumferential deformation. The hard-soft complex microstructure can suppress stress concentration within the tissue. Coherent nanotwin boundaries along the longitudinal direction of the nanowires increase their resistance to bending fracture. The unusual biomineral, which exploits the inherent properties of each component through multiscale structural design, provides insights into the evolution of antifatigue structural materials.

Currently, there is limited research on the in situ forming process of thermoplastic prepreg tape winding, and the unclear impact of process parameters on mechanical properties during manufacturing is becoming increasingly prominent. The study aimed to investigate the influence of process parameters on the mechanical properties of thermoplastic composite materials (CFRP) using laser-assisted CF/PPS winding forming technology. The melting point and decomposition temperature of CF/PPS materials were determined using DSC and TGA instruments, and based on the operating parameters of the laser-assisted winding equipment, the process parameter range for this fabrication technology was designed. A numerical model for the temperature of laser-heated CF/PPS prepreg was established, and based on the filament winding process setup, the heating temperature and tensile strength were simulated and tested. The effects of process parameters on the heating temperature of the prepreg and the tensile strength of NOL rings were then analyzed. The non-dominated sorting genetic algorithm (NSGA-II) was employed to globally optimize the process parameters, aiming to maximize winding rate and tensile strength. The results indicated that core mold temperature, winding rate, laser power, and their interactions significantly affected mechanical properties. The optimal settings were 90 °C, 418.6 mm/s, and 525 W, achieving a maximum tensile strength of 2571.51 MPa. This study provides valuable insights into enhancing the forming efficiency of CF/PPS-reinforced high-performance engineering thermoplastic composites.

The increasing use of lightweight fiber-wound composite pressure vessels in energy-storage and transportation applications has heightened the need to understand impact-induced structural damage and the associated degradation in residual load-bearing capacity. Despite their superior stiffness-to-weight ratio and corrosion resistance, these vessels are susceptible to low-velocity impacts (LVI) during handling and service, which may compromise their residual burst capacity. To address this issue, the present study adopts a sequential numerical procedure to examine the dynamic impact response and post-impact failure behavior of thin-walled composite vessels. The modeling approach uses ABAQUS/Explicit and ABAQUS/Standard sequentially with VUMAT and UMAT subroutines, incorporating the LaRC05-based damage model and a cohesive-zone interface model to capture both intralaminar and interlaminar degradation. With increasing impact energy, the peak impact displacement increases, indicating more pronounced deformation. The residual burst analysis further shows that higher impact energy reduces the vessel’s calculated burst pressure. The predicted burst pressure of an undamaged configuration is 22.95 MPa, serving as a reference for evaluating strength degradation under impact loading. The findings contribute to a deeper understanding of impact response and residual strength behavior in composite pressure vessels, providing a numerical reference for impact-related structural design and safety optimization in advanced energy systems.