No abstract

Based on Technology Acceptance Model (TAM), this paper constructs the augmented reality electronic publication communication effect model (AREPCEM) and analyzes the data among youth. It is found that the first-level index (use and recognition) and second-level indicators (external variables, perceived usefulness, perceived ease of use, satisfaction, dependency) have positive relevance to audience recognition among youth.

In order to study the effect of strain rate effect on the simulation precision of fiber reinforced composites, the dynamic enhancement factor (DIF) was introduced to modify the modulus and strength of the composite, and the modified Hashin failure criterion was used to establish a three-dimensional progressive damage constitutive model of composite materials which could consider the strain rate effect. The model is embedded into the Abaqus software by VUMAT subroutine, and the simulation of the projectile penetrating the fiberglass reinforced composite laminates is carried out. The simulation results are compared with the experimental results and the constitutive model simulation results without considering the strain rate effect. The results show that the constitutive model with strain rate established in this paper can accurately simulate the process of projectile penetrating the laminates. Compared with the simulation results without strain rate, the accuracy is increased in the model with strain rate, respectively by 14.1% at the penetration speed of 1.8 m/s and by 22.7% at 3 m/s. The errors, between the simulation results of without strain rate and that of the experiments, are increased with the increase of penetration speed, and increase from 28.7% of 1.8 m/s to 36.9% of 3 m/s. The simulation error of constitutive model with strain rate is relatively stable.

A multidisciplinary optimization method about the thickness of engine hood based on pedestrian protection was proposed. The impacting zones of engine hood where HIC values of original engine hood were higher than the safety value of 1000 were selected as the cases of optimization. At the same time, the stiffness of torsion of engine hood and the deformation distance between the hood and the underneath hard parts in the engine bay were taken into account. The objective was the minimization of hood deformation above where the hard parts were located. The first type of constraint was that the HIC values were less than the safety value 1000 in the selected cases of optimization. The second type of constraint was that the torsion stiffness of engine hood was higher than that of the regulation. The pedestrian protection optimization model about the thickness of engine hood was constructed and solved. The results of optimization indicated that the obtained thickness by this method improved the performance of pedestrian protection.