Advanced Materials Research Vol. 510

Abstract: The geometric error is the important aspect of affecting the process accuracy of NC machine. In order to improve the machining accuracy, the article gives a new method to compute the cutter path by making use of the error model of MAKINO based on multi-body theory. By comparing the errors which is not divided with the errors that is divided, the study shows that dividing the errors into different regions is an effective method that can improve the accuracy of machine tools. Combing the new method and the error compensation based on multi-body theory, the error partition can be easily used in the compensation of machine tools by modifying the G code.

Abstract: Sources and measurement of cutting forces are studied to establish the steady-state cutting force prediction model. Modeling of work piece machining error is analyzed, a simplified process coordinate system is established, and the mathematical solving model of machining error within the work piece is given. The cutting force due to work piece bending deformation is studied, a work piece deformation factor error model is established based on steady-state cutting force and the prediction simulation of cutting forces and machining error is achieved.

Abstract: The regenerator of Stirling refrigerator is normally installed a contact sliding sealing ring, but if the sliding sealing ring working hour is overlong, it would cause wear heavily, and reduce the service life. This paper focus on resolving this problem: use a clearance seal device, which without leakage under the high pressure test, instead of the sliding sealing device. Meanwhile, use the clearance seal device would eliminate contact wear which would cause the leakage losses. Therefore it is fairly important to establish a theoretical model to imitate leakage process in the clearance seal device, analyze the factors which influence clearance seal, and find a solution to improve clearance seal in Stirling refrigerator.

Abstract: Spline shaft is widely used as one of the important parts in machinery, It is complex in manufacturing process, its appearance quality and size precision and the comprehensive mechanical performance requirements of high. Small modulus involute spline rolling technology has many advantages, Can reduce the cost, improve quality and The use of reliable.Cold rolling process is currently the main processing mode for small module splines, but the special machine is too expensive.This article describes how to achieve a small modulus spline cold rubbing process by transforming an existing thread rolling machine while without buying the expensive special machine. The focus is on the problems encountered in the process of equipment transformation: design of cutters, control of the workpiece diameter and how to solve the fault spline gear in the course of processing.

Abstract: Fuel system is the most vulnerable system on fixed wing aircraft. When penetrated by threat propagators, it is liable to be damaged by combustion and explosion. Thus, fire/explosion suppression for fuel system are important measures to improve the aircrafts survivability. In this paper, the whole aircraft vulnerability model which consists of aircraft configuration, structure, and systems is constructed by CATIA software, the basic steps for vulnerability quantitative computation are descried, and the computing formulas of three kill modes are presented. The vulnerability of one aircraft before and after adopting fire/explosion suppression measures are analyzed. The results show that fire/explosion suppression measures can effectively decrease the aircrafts vulnerable area and kill probability.

Abstract: For making enterprise to flexible manufacturing, some scheduling optimization algorithms are correspondingly designed for the main producing equipments, such as the machine tool, transport vehicles, warehouse work machine and so on. At the same time, VC language is used to develop a simulated procedure of a small-scale workshop. Then these scheduling optimization algorithms are inserted to the simulated procedure. At last a simulated example proves the availability of these algorithms for they can shorten the period of manufacture, improve manufacturing efficiency and achieve the purpose of flexible production.

Abstract: This paper presents a heave compensation system for base plate used in 3000m deep-water exploration ship according to the sea conditions and the compensation requirements. The heave compensation system consists of a passive heave compensation system and an active heave compensation system. The passive heave compensation system with two hydraulic circuits and two air circuits is described, and the working principle is analyzed. The active heave compensation system, which consists of the hydraulic compensation cylinder, the hydraulic system using the closed-circuit and the electrical control system, is also established, and the working principle is investigated. The heave compensation system can keep compensation tension in the wire rope within certain range and make the rod run at design range (±500mm), which can avoid the serious equipment damage and a safety hazard to operators.

Abstract: With the platform of ANSYS finite element software, on the base of optimal residual stress theory established a crankshaft fillet rolling model under conditions of kinetic analysis and conducted a simulation test. The dynamic changes of residual stress and effective stress are given by different amounts of feed rate and the rolling pass,and comes to the conclusion that 480Q crankshaft when rolling at the depth of 0.66mm the effective rolling stress is the largest, residual stress will increase in the plastic deformation process,for the enhanced production of the actual crankshaft rolling provides quantitative guidance.

Abstract: For coiled flexible shells, theoretical formulas of calculating the stress distribution are derived and applied to initialize the prestressed status of the shells before deploying. Following the prestress initialization, dynamic simulation of elastic and elasto-plastic deployment processes with large deflections of the shells is conducted by explicit time integration. It is shown that the simulation based on prestress initialization method is feasible and efficient. Comparing the deforming process and the energy history of the elastic deployment with that of the elasto-plastic deployment, the effects of plasticity are embodied as slowing the deployment process down and speeding the kinetic energy dissipation up, while making the shell unable to return to its original configuration, and keep more residual strain energy. A primary approach to decrease the effects of plasticity is improving the initial prestressed status of the coiled flexible shells.

Abstract: In high-speed cam mechanisms, the output motion and positioning accuracy are affected greatly by residual vibrations. To reduce residual vibration, non-uniform rational B-splines (NURBS) is employed to reconstruct the cam profile. Based on elastic dynamic theory, this paper designs the multi-objective dynamic optimization model of high-speed cam mechanisms, and proposes an improved artificial fish swarm algorithm (IAFSA) to optimize the cam profile. Utilizing the taboo search strategy, NURBS profile is optimized twice with variable parameters. By adjusting parameters of NURBS, dynamic characteristics of the follower motion curve are improved, and the residual vibration is reduced. Finally, an optimization simulation example is given to demonstrate the usefulness and effectiveness of the approach.