Papers by Author: Liang Li

Abstract: Motorcycle fender is one of the main components of motorcycle,fender structure directly affected it's comfort and security properties.In this paper, the finite element modeling and dynamic response were analyzed using NX 8.0, and found its natural frequencies and mode shapes. On the basis of the fender structure modeling on different road with the same speed, this paper investigated the several factors affect the vibration motorcycle and analyzed true fender of the motorcycle and did comparative analysis with the modal analysis results. It is helpful to the design of the fender structure and the estimation of the fender fracture. Key Words: Fender;finite element method;modal;Dynamic response

Abstract: With the development of the aviation industry, the aircraft's increasingly high performance requirements, the overall application of thin-walled structural components became more widespread. However, due to the complex structure parts, thin wall, high precision machining process was complexity, the cutting force, cutting heat, clamping force under the influence of other factors, prone to machining distortion, and with the lower part wall thickness, decreased in rigidity, it was difficult to ensure processing quality. In this paper, we proposed several effective aviation thin-walled parts machining precision control program to solve the problems in the processing of machine structural characteristics of thin-walled parts .The results of experiments and production practice proved that these methods effectively control the air thin-walled parts machining precision machining to meet quality requirements, while reducing the processing time, improve processing efficiency, it was convenient and efficient processing methods.

Abstract: Model based definition (MBD) is the new trend of CAD technology development. Concerning with current situation of manufacturing industry of our country, the solution of model based digital design and assembling is presented and key issues of its implementation. It enhances design efficiency and product manufacturability.

Abstract: Free-wheel hub plays an important role in automobile starter system, so there is higher quality requirement on geometry and precision. In order to improve the efficiency and comprehensive functions of the part, according to the features of the lower part with involute small module internal helical spline, the rotary forming technology was put forward, and the forming process was simulated by the DEFORM-3D software. In the die design, the use of rotary punch made the process of rotary forming achieved in common hydraulic press, and can serve as an important reference to the design of forming process and die structure of similar part.

Abstract: Thin-wall components were widely used in aerospace products. However, due to the special shape of the structure and the poor machinability, traditional technologies were hard to mill the thin-wall components, milling vibration influenced in the machining process. In this paper, analytical and experimental identifications of the chatter frequencies in milling processes were presented. In the case of milling, there are several frequency sets arising from the vibration signals, as opposed to the single well-defined chatter frequency of the unstable turning process. Frequency diagrams are constructed analytically and attached to the stability charts of mechanical models of high-speed milling. We proposed the corresponding technological measures to prevent deformation.

Abstract: Rigid-viscoplastic finite element method was used to analysis the cold extrusion of the external boss and ring gear. Some groups of numerical models were built with different design parameters of die, geometric parameters of gear, processing conditions, and the service loads were investigated. Form the investigation; we predicted the forming defects occurring in the practice. Based on Archard model the lives of dies were predicted. The conclusion above has more guidance to the production.

Abstract: Based on building the 3-D elastoplastic FEA model on the M93 guide cylinder and its mould, the process of cold extrusion was simulated by the numerical simulation analysis. The varying rules of extruding forces, velocity, stress as well as metal fluent regulation were obtained. The results of simulation agreed with the practice. This research played a guiding role on the simulation of the cold extrusion and the design of the die set.