aThe polyvinyl butaral (PVB) interlayer of automotive windshield plays an important role in the protection of both pedestrian and passenger, the mechanical property of PVB material should be in-depth studied. In this article, the systematical uniaxial tensile experiments of PVB material under high strain rates are conducted, the strain rates range from 125.6 to 3768 s À1. The results of experiments show that there exists a phenomenon of stress spurt caused by the stress hardening in the final stage of tension, and the strain rate exerts great influence on mechanical property of PVB material. Further, the data fitting basing on Mooney-Rivlin model is carried out, it is found that the fitting results are consistent with the experiment data, which means that the Mooney-Rivlin constitution model can describe the large deformation behavior of PVB material. At last, the rate-dependent mechanical behavior of the PVB material is further investigated in this article. On the basis of the experiment results and Johnson-Cook model, a rate-dependent constitutive model is proposed to describe the tensile mechanical property of PVB material under high strain rates. This work will be beneficial to the simulation and analysis of automotive collision safety and pedestrian safety protection, which are related to damage of automotive windshield.

Pipeline inspection gauge (PIG) is often blockage in the aging pipelines of stacked objects owing to the limitation of its passive control. In this study, a novel sealing disc with multi-jointed pneumatic webbed foot was designed which can achieve partial active control and ensure better seal performance. A finite element method (FEM) was proposed and successfully verified, then the bend performance of the sealing disc with single inflated foot was compared with whole inflated feet using the FEM, and the results show that they have good consistency. Next, the effects of two kinds of materials and five structural parameters on the performance of the sealing disc were studied using the FEM. The results show that the multi-material structure has batter performance on the bending angle and the expansion ratio compared to the same materials. As the air pressure grows, the position parameter of the joint (he) has little effect on the bending angle as well as the expansion ratio, and the bottom disc thickness (hd) has also slightly influence on the expansion ratio. Meanwhile, the thicker the webbed foot thickness (ht), the smaller the slope angle (β) and the thinner (hd), the larger the bending angle; the smaller the slope angle, the thicker the webbed foot thickness, the larger the expansion ratio. The conclusions obtained in this paper are beneficial for the design and optimization of PIG sealing discs for actively controlling. The research results provide theoretical reference for the study of intelligent and efficient pipeline pigging technology.

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