Ren Luquan

Preliminary studies on the basic factors of bionics

The bionic consciousness, idea, and practice opened a unique path for the progress of mankind, the development of the society, and the innovation of science and technology from the subconscious bionic activities of the ancient humans to the significant bionic designs in modern engineering. Nowadays, driven by the practical demand of human beings, bionics becomes an important factor for the sustainable development of technology. A lot of new and outstanding innovations have been produced through the effective interactions between bionics, technology, and demand. The stronger the interactions, the greater the innovation success would be. In this article, the basic factors such as the connotation, characteristics, and interactions of bionic demands, bionic models, bionic simulations, and bionic products were explained, which are the indispensable basic knowledge for improving the ability of innovation especially for the original one, realizing the design and innovation of new technology and manufacturing for better bionic products.

Numerical Analysis of Aerodynamic Noise of a High-Speed Pantograph

The aerodynamic noise of pantograph is one of the most important noise sources of high speed trains. Therefore, the reduction of the aerodynamic noise of pantograph becomes very important for reducing the total noise level of the high-speed trains. In this paper, the distribution of dipole sound sources at the surface of a single-arm pantograph and the noise radiation from it are predicted numerically by the combination of incompressible fluid flow analysis using the finite element method (FEM) and acoustic analysis using the boundary element method (BEM) at speed of 300km/h. The objectives of this calculation are to locate the noise sources on the surface of this type of pantograph and to understand the mechanism of the aerodynamic noise radiation. The analysis results indicate that: the aerodynamic noise of the high-speed pantograph is induced by the vortex shedding, the main noise sources of this single-arm pantograph are the pantograph head, knee, arms around knee and foot region, the aerodynamic noise of this type of pantograph is mainly the low-frequency and mid-frequency noises.

Investigation of Micro-wear and Micro-friction Properties for Bionic Non-smooth Concave Components

Five kinds of 45# steel samples with concave features on the surface were manufactured using Laser Texturing Technology (LTT). Optimum design theory was used to design the experiment, and a two-level orthogonal table — L16 (215) design was adopted. Micro-wear and micro-friction experienced by samples with concave surface features and samples with smooth surfaces were compared experimentally. The wear resistance of samples with concave surface features was increased most, and different surface morphologies had different effects on friction and wear properties.

Dynamic system identification of Audi disc brake under anti-lock condition

In this paper, a dynamic test of an Audi disc brake is performed on the JF-132 vehicle brake tester. The ARX model of the brake dynamics is developed. Based on measured data, model structure is determined, and the model parameter is identified employing the optical instrumental variable method. Through validation of residual whiteness and comparison of different observed data, the precision of the model is confirmed.