Abstract: Based on the theory of multi-body system dynamics and simulation software ADAMS/Car, the whole vehicle model was established. Afterwards by means of pylon course slalom, the accuracy of modeling was tested. The analysis and evaluation were later made to draw a conclusion that the handling stability of model needed improved. So as to improve the handling stability, the index lateral acceleration, yaw rate, side slip angle were taken as target function while suspension stiffness parameters were designed variables. Optimization of vehicle handing stability was practiced by applying second-order Response Surface Methodology (RSM) model. The relationship could be obtained by least square method obviously. Moreover applying with linear interpolation the final objective function was decided. The minimum of final objective function was the optimal result. Simulation analysis was performed again for the whole vehicle model by parameters modification. Subsequently, the results showed that this method greatly improved handling stability.
Abstract: This paper mainly designs several projects to analyze the deformation of crash box. Through analyzing the crushing distance, energy absorption and axial force variation, which is under different schemes and low crash speed, gets that: a front crash box slot is necessary; Filling foam allows the specimen to absorb more energy and makes the carrying capacity changing more stably. Finally, we compared simulation results with the experimental results, and on this basis, providing improvement program means.
Abstract: Support reliability of missile weaponry is very important for its fighting capacity’s forming. The missile support process was first studied. Then based on the analysis of influence factors of human reliability, neural network structure of missile support reliability was presented with the aid of neural network’s theory and methods. With case study, the relation between human reliability’s influence factors and support reliability. It can provide management information and technology plan for evaluating support personal reliability, personal selecting and training.
Abstract: The fracture toughness of HTPB propellant has a significant rate effect. In order to establish a fracture criterion considering rate effect for HTPB propellant, experiments were conducted at different loading rates. Two kinds of specimens were used to get the fracture properties. Stress intensity factor and J-integral were obtained by the single edge notched tension specimen test. A power law cohesive zone model was obtained by the experiment based inverse method. Through comparing we found that the stress intensity factor and J-integral cannot model the rate effect in fracture process. The cohesive zone model (CZM) has a constant critical separation distance at different loading rates and has a capability to model the rate effect during the crack initiation and propagation process. A finite element simulation in ABAQUS was given to demonstrate its capability to model the crack propagation.
Abstract: Stretch-Blow moulding (SBM) fabricate process is a well known method to produce PET bottles. During the construction procedure, PET surface temperature distribution controlled by infrared heating is the key factor about manufacture technique for the better quality of PET. This paper focuses on how to measure and estimate temperature distribution on the surface of semi-transparent polymers so that we can make sure the proper position and intensity of the infrared lamb. We use infrared camera to detect the real temperature distributions and C++ object-oriented programming to estimate the infrared radiation (IR) results by adaptive finite volume method (Adaptive FVM). The numerical results have been compared with experimental results and the consequence is satisfied. Multiple lambs’ cases and the interior temperature distribution in PET will be discussed in future.
Abstract: The kinematics analysis is carried out on a kind of 3-urps parallel mechanism (pm) with 6-dof. The positional inverse solution and Jacobean matrixes which is used to analyze the dexterity of mechanism are derived. Condition number is used as evaluating indicator of dexterity in this article, and its’ three-dimensional graphs are drawn when this mechanism in different attitudes. It is indicated that dexterity of moving is excelled than the rotary movement’s for this pm. The optimum dexterity can be obtained in the center of mechanism’s workroom, which can be applied to further characteristic analysis and kinematic design of mechanisms.
Abstract: Factory layout is NP problem. There are many methods to solve it ,such as engineering diagram, flow chart method, various heuristic algorithms, SA( simulated annealing) and GA(genetic algorithm) .ACO (ant colony optimization) is used to solve it in this paper. The logistics costs exist between two workshops that are treated as pheromone that guides ants to search the best solution. Smaller logistics cost is, stronger the two workshops of relation is. In the process of optimization theworkshop with low logistics cost is more likely to be chosen, which minimizes the system logistics cost. Compared with GA, ACO has the advantage in speed. The mean value of the solution, the best solution, the worst solution is better too. More the number of workshop is, more obvious the superiority is.
Abstract: Breech mechanism serves to close the breech, fire the ammunition and extract the cartridge case in firing process. In firing process, breech mechanism completes complicated actions, bears tremendous impact forces and produces huge percussive forces between components. Its major fault mode is grain abrasion caused by dry sliding friction. There are no feasible and practical technologies to simulate and predict the abrasion failure life of key parts for breech mechanism. A new simulation and prediction method is firstly put forward in this paper. Based on Pro/E and ADAMS, the virtual prototype of breech mechanism of semiautomatic vertical sliding-wedge type is established. To validate its precision and affectivity, qualitative and quantitative verification methods are adopted to check the virtual prototype of breech mechanism. Virtual prototype produces key parts’ load spectrums and failure thresholds. Dry sliding friction and abrasion experiment provides abrasion rules of typical materials. Finial simulation and prediction results are given as abrasion thresholds and operating items, which provides sufficient references for breech mechanism’s maintenance and safeguard.
Abstract: In order to reveal the adjustment principle of prestressed cutting on the residual stress of hardened bearing steel GCr15, a three-dimensional thermal elastic-viscoplastic finite element model was developed using an Arbitrary Lagrangian Eulerian (ALE) formulation. Several key simulation techniques including the material constitutive model, constitutive damage law and contact with friction were discussed, simulation of chip formation during prestressed cutting was successfully conducted. At the prestresses of 0 MPa, 341 MPa and 568 MPa, distributions of residual stress on machined surface were simulated and experimentally verified. The results indicated that residual compressive stress on machined surface were achieved and actively adjusted by utilizing the prestressed cutting method; meanwhile, within the elastic limit of bearing steel material, the higher applied prestress leads to the more prominent compressive residual stress in the surface layer and subsequently the higher fatigue resistance of the part.
Abstract: By using the unique characteristics of high pressure water jet, sound test, analysis and recognition techniques combined with high pressure water jet, collecting target reflected sound signal characteristic value, then by the analysis processing, to achieve recognition for classification purposes, can form a kind of brand-new landmine detection method. For the ultimate realization of the target of effective detection and classification, it must be determined on the reflected sound signal of water jet hydraulic parameters and reasonable choice of the walking device and a signal acquisition device parameters. Effects on reflected sound signal characteristic value quality parameters include: nozzle diameter, jet pressure, nozzle and the target of target distance, jet angle and jet scanning speed. By parameter optimization, the system can complete identification of material and geometry of eigenvalue.