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The three-dimensional modeling and analysis of virtual pavement are conducted for the complex and diverse test pavements in the vehicle reliability driving test. Firstly, a complete pavement unevenness acquisition system is constructed, and secondly, the classification and processing methods of different pavements are determined according to the actual working conditions and load spectrum data of the test pavement in the test site to provide a theoretical basis for the virtual pavement modeling. At the same time, considering that the test pavement also includes various complex pavement conditions such as curves, slopes and lateral inclination, the structural composition and differences of plane curves, longitudinal ramps and cross-sections are analyzed to provide a guarantee for the further establishment of an accurate 3D pavement model. Finally, the 3D virtual pavement model of typical test pavements is established according to the theory and methods of the above research, and the accuracy of random pavement reconstruction is analyzed, which provides accurate and effective technical support for the simulation of automobile reliability driving tests.

Suction cups of cephalopods show a preeminent performance when absorbing irregular or flat objects. In this paper, an octopi-inspired suction cup, driven by hydraulically coupled dielectric elastomer actuators (HCDEAs), is proposed, which is considered to be controlled easily and have compact structure. To investigate the performance of suction cups, experiments have been conducted to clarify the effect of the pre-stretch ratio and chamber angle on suction forces. It could be seen that both factors have a complicated influence on suction forces, and the best performance obtained was a reasonable combination of the pre-stretch ratio and chamber angle. Here, we achieved a maximum suction force of 175 mN with λp = 1.2, α = 23° under a DC voltage of 3500 V. To enhance the capacity and adaptation of the suction cup, flat objects of various types of materials were introduced as targets. Experimental results displayed that for tested materials, including a dry/wet acrylic plate, CD, ceramic wafer, and aluminum plate, the suction cup showed outstanding performance of absorbing and lifting the target without any damage or scratch to them. Our research may serve as a guide to the optimal design and provide insights into the performance of the HCDEAs-actuated suction cup.

As a novel kind of focus tunable lens, dielectric elastomer actuated liquid lens has a compact structure, fast response, low cost, and outstanding tunability, which makes it attract extensive attention. Here, we present a computational model of a dielectric elastomer actuated lens with dual chambers that consist of three elastic membranes and two disconnected chambers filled with conductive and transparent liquid. The intermediate layer actuated by applied voltage deforms, changing the curvature of passive membranes and obtaining a new focal length. The simulation results calculated by the shooting method with two guessed values agree well with the experimental results. Based on this model, the effects of a set of parameters, including chamber radii, shear modulus, permittivity, prestretch ratios, and injected liquid volumes, on the tuning performance of the lens are analyzed. It is found that, by regulating the liquid volume in each chamber, both the initial focal length and the tuning range can be adjusted easily. Under the condition with specific liquid volumes, the lens possesses both positive and negative focal length during voltage actuation, indicating promoted tuning performance, which is acclaimed for optimal design.

This paper presents a dynamic model of asphalt pavement by considering the characteristics of moving tyre load, visco-elastic performance of material and layered system of pavement. The pavement is defined as an infinite layered system with the tyre load moving at a constant speed, and asphalt concrete (AC) is characterised as a kind of visco-elastic material. Using the spectrum analysis method, a complex tyre load is decomposed into a series of harmonic loads. Based on the frequency characteristics of a linear system, a universal formulation pattern for differential visco-elastic constitutive relations is provided. And then, a model is set up to analyse the dynamic response of asphalt pavement under moving harmonic load, and then to extend to the arbitrary moving load according to the superposition principle of a linear system. The dynamic responses of seven typical semi-rigid base asphalt pavements are analysed using the model. Analysis results indicate that the tensional strain at the bottom of the AC ...

as the road dynamic response is a transient and weak signal with strong noise, it is very difficult to extract their feature, and the traditional Fourier filtering technology is not suitable for the non-stationary signal processing. Using the "multi-resolution analysis" feature of wavelet Transform, the signal can be decomposed in the specific frequency band. Furthermore, the global reconstruction after processing the high frequency decomposing coefficients can separate the valuable components from the noise successfully. Based on the analysis of data collected at the scene to prove that the signal processing method can effectively solve the de-noise problem of the road dynamic response.

The study on dynamic response of pavement under real transportation load is one international thermal topic. In view of the characteristics of the construction process of asphalt pavement and the dynamic response under heavy truck, one strain sensor was built up which can detect the dynamic strain of pavement under moving load. And corresponding tests were carried on in laboratory and in field road. It's found that the sensor not only can bear the destruction of high temperature and shearing, but also can satisfy the test requirement on dynamic transfer. Without especially protection, the survival rate in field road arrived to 82%. It's also found that the influence of the rigidity of the base layers on the dynamic response is large, and found that the dynamic strain at the bottom of each surface layer under moving load presents not only tensile strain but also compressive strain.