Applied Mechanics and Materials Vols. 494-495

Abstract: Retracted article: This paper is about structure optimization of agricultural vehicle frame which adopts the method of adding strengthen box ,set up Frame and strengthen box parameterized mode Based on APDL , Using the optimization module of ANSYS to optimize the shape of the box and place got obvious improvement to the bad stress of longitudinal beam,Thus the overall performance of the frame is improved.

Abstract: Movement of large ship in waves is one of the important factors which can induce ship surface air turbulence; it is bound to a large impact on the air-flow field on deck, which affect the safety of the aircraft landing. In order to study the change of the flow field in the process of movement of large ship and its influence on aircrafts take-off and landing, under the same experimental condition of the unsteady condition. We set up 3d model, observe and analyze the ships air-flow field changes in the movement. Finally, calculate the results and give the effect of the aircraft landing in the key areas.

Abstract: Finite element model of airflow field inside the face-blowing duct of air conditioning system on a light bus was established according to its special structural characteristics. With computational fluid dynamic (CFD) theory and method, the airflow field was simulated in software Fluent to obtain the airflow distribution to each outlet. Based on requirements of riding comfort performance, structural optimizing measures were presented to get smoother airflow field inside and more reasonable airflow distribution of outlets.

Abstract: A large diameter cylinder prepared by thick wall pipe as raw material presents the shortfalls such as high cost, difficulty in procurement, the increasing amount of labour and processing cost. This work proposed a large diameter cylinder with high precision. By conducting process experiments and compared with the preparing process of existing large diameter cylinder, the preparing process of the large diameter cylinder in this work is proved to be practical and economical.

Abstract: In order to analyze the force of the anchor chains and the cable in the crane-system with a floating base, firstly the system is simplified to two-rigid-body model and the anchor chains in the system are in symmetric layout; then the motion response of the system as well as the force of the anchor chains and the cable are solved by use of discrete time transfer matrix method, lastly the time history curves of motion of the system and the force of the anchor chains and the cable are obtained. The results of numerical simulation show that the roll motion has greater influences on the system comparing with sway and heave, the amplitudes of sway and heave are small. Furthermore, the force of the anchor chains are mainly caused by the roll motion while the force caused by sway and heave are relatively small.

Abstract: The precision control is the key technology for reverse engineering. Focus on analyzing the reasons of the error of reverse retrofit design of the product, the factors, affecting the precision of the retrofit design of the product, through four stages which including product model, development & design, simulation, evaluation & acceptance, is proposed. By the example, through the distribution and control of precision rationally, the accuracy requirement of the reverse retrofit design of the product is met, effectively.

Abstract: Stress (P) and pressure time (T) are the two main factors which affect the bayonet tube shell shrinking size. In this paper, we study this two factors. Double factors regression analysis and variance analysis method were used to analysis data. PT tube shell shrinkage model is set up to explore the correlation of tube shell shrinkage size and pressure (P) and the pressure time (T) and its change rule. Results show that the established PT contraction model can well reflect the relationship between the tube shell shrinkage size and the PT factors.

Abstract: Based on studying the existing electric wheelchairs for disabled are not well adapted to a variety of road conditions, broken through the structure of traditional wheelchairs, a design proposal that can make electric wheelchair achieve the function of climbing stairs and walking was putted forward and a novel mechanism was designed. The mechanism can make the crawler chassis and the wheels of wheelchair switch when needed, and make the wheelchair travel freely and flexible on the ground or on the stairs. The finite element model of the mechanism was built, and the strength analysis was carried out. The strength analysis provide the theoretical basis for the prototype manufacture.

Abstract: Double loop cutters arrangement can settle the contradiction between rotational inertia of the tool magazine and the dimension limitation of the cutter head effectively, and increase the store of tools. Disc type tool magazine with double loop cutters arrangement is designed and researched. The spring steel 65Mn is used to manufacture elastic cutter fixture as the holding device for its inner and outer loop tools. The dynamic deformation of elastic cutter fixture is discussed. The entire geometric movement process of elastic cutter fixture from being opened by the tool holder to accomplishing the whole action is analyzed. The effect and trend of inner stress caused by geometric deformation are studied. Furthermore, the force condition in each part of tool fixture can be calculated, thus predicting the motion stability and reliability of the elastic cutter fixture, and providing theory references for the design of elastic cutter fixture.

Abstract: Because of the differences in spindle speed and extended length of micro milling cutter, Tool life and machining surface quality vary markedly. Therefore, a geometric model of carbide end mill whose diameter is 0.2mm is built. With free meshing method, meshing density is set up reasonably, which ensure the rationality of the built finite element model. On the premise of considering the extended length of the micro milling cutter, apply linear load on the main cutting edge and front-cutting edge, carry out the deformation and stress analysis using finite element software. Applying different spindle speeds under four extended lengths, through comparing maximum stress and strain under four extended lengths, change rules are summarized and the extended lengths of the tool suited for micro-milling are achieved.