Advanced Materials Research Vols. 479-481

Abstract: In this research, the numerical simulation of torsional strength for single and double layer of high parameter welded metal bellows mechanical seal is carried out and the stress-strain diagram is obtained. Besides, the torsional strength is tested by experiment and the result of it is compared with the simulating results, and the feasibility and availability of numerical simulation have been proved. The result provides a guide for the structural optimization and the calculation of torsional fatigue failure of welded metal bellows.

Abstract: The paper proposes three kinds of improved main-beam structural style of electric single-girder crane and established FEA model for each style. The stress values of stress concentration points of improved structures have been compared to traditional structure. The fatigue strength of points where easily occur fatigue failure have been analyzed using local structure stress method and Master S-N curve. According to fatigue analysis, the minimum number of effective cycles is N=3.73×105, which can meet the design specifications well. This study will provide some ideas for main-beam design and improvements.

Abstract: In order to research the fatigue fracture problem of the rear axle of a China-made car at the reliability test stage on the durable enhancement roads of proving ground, and the strain loading spectrum of the rear axle fracture location and the weak points of the finite element analysis was measured. The fatigue damage of the broken crack at the rear axle on the durable enhancement roads was calculated and contrasted detailedly. At the same time，a six-channel MTS coupling system is used to conduct the vibration mode frequency sweep to the rear axle and car body of test car and the benchmarking car，and through vibration frequency sweep，an analysis of the reason of differences between the two cars and its relationship with the car body vibration frequency is made. The enhancement test and frequency sweep results show that the fatigue damage of two vehicles focuses mainly on the washboard road，the impact of the speed on the fatigue damage of the test car fluctuates significantly, the damages of the two cars vary greatly when the forced vibration excitation frequency of the washboard road is greater than 20Hz and the vibration modal frequency of the rear axle is close to the excitation frequency of the washboard road, causing high stress distribution and then fatigue fracture to the rear axle of the test car. The test results have provided an important basis for the structural improvement of the broken rear axle and the enhancement in the fatigue strength of the rear axle.

Abstract: Stiffness and strength simulation of Remote Control Weapon Stations (RCWS) at the design and demonstration stages should be convenient, quick and accurate. In order to satisfy those needs, this paper develops a stiffness and strength quick simulation template for RCWS barrel, which is based on co-simulation environment ANSYS Workbench, and using of JavaScript language. In the end, the stiffness and strength of a RCWS barrel is analyzed by this template.

Abstract: To determine the stress spectra of a vehicle frame under random road excitations, A mathematical model was been established using the Euler-Bernoulli beam elements and spring-damper elements for the multiple-degree-of-freedom (MDOF) vibration of the vehicle frame with a finite element method, and adopted a virtual excitation method to construct virtual road excitations based on four points, i.e., front and rear wheels, thus we offered a method for calculating the statistical characteristic of the random vibration response of the vehicle frame based on the virtual excitation method, and realized stress spectrum analysis of the random vibration of the vehicle frame. The results show that combining the virtual excitation method and the finite element method for random vibration analysis, maintained the theoretical precision and greatly simplified the calculation , thus provided a feasible way for stress spectrum calculation in fatigue analysis of a vehicle frame under random excitations.

Abstract: According to the factual demand of produce, some corporation wants to enlarge the capacity of the idle from 65t to 75t. This paper aims at the changing ladle which the capacity is 75t. It makes research to the iron ladle's promotion process and stress analysis. This paper uses ANSYS-Workbench software to make the finite element analysis of the iron ladle and extracts the largest stress, strain and the location. Then this paper analyses whether the changing ladle can be fit for the intensity demand or not so that it could provide the important theory gist to the corporation

Abstract: In order to study the stress distribution of dual-frequency vibrating screen and ensure the screen box has sufficient strength and longevity, a finite element model of dual-frequency vibrating screen was built, and the stress, modes and fatigue life of the screen box were analyzed. The results indicate that, the stress concentration appears at the contacting parts between the crossbeam and the stiffener of motor seat, the crossbeam, L-type stiffening plate, baffle of material added and screen box. The middle of crossbeam and the L-type stiffening plate are weaker parts of fatigue, they are easily fatigue failure under high frequency vibration.

Abstract: Air-bearing is a core component of air-bearing rotary stage. The weakness that the air-bearing has the low load capacity and stiffness has been concerned about by domestic and foreign scholars. So how to improve the load capacity and stiffness has become a serious problem. In order to improve the load capacity and stiffness of the air-bearing rotary stage, in this paper, we improved structure of Zhang Wenjie and others’ high-precision direct-drive air-bearing rotary stage. The gas film of air-bearing has been meshed by GAMBIT software, and we use FLUENT software to obtain the carrying capacity features of the gas film. Finally, the structural static force of the precision air-bearing rotary stage will be analyzed by ANSYS software. The analysis results show that: the structural design of the precision air-bearing rotary stage is reasonable, and this structure can provide a larger range of loads. Even in heavy load conditions, a larger deformation will not occur any more. It has a good practical value, and also can be widely used in high precision equipments.

Abstract: First, several widely used models of the multiaxial low-cycle fatigue life prediction based on the critical plane approach were presented in this paper, and the predicted results of these models for a medium carbon steel under the condition of multiaxial low-cycle fatigue loading were compared. Second, the stochastic expressions and probability density function curves of the fatigue performance parameters were obtained by probabilistic analysis of the medium carbon steel fatigue data. Finally, the probabilistic model of the multiaxial fatigue life prediction was simulated by Monte Carlo Method, which should provide a basis for the reliability analysis of engineering components subjected to the multiaxial complex loads.

Abstract: We conducted a series of steady-state experiment on a novel anaerobic-MABR process used for COD removal of esterification wastewater. The results showed that COD removal efficiency remained above 90%, even if the COD loading was up to 3000mg / L, the removal rate still remained above 80%. To ensure the final water quality, biological aerobic segment played a decisive role in anaerobic-MABR process. Hollow fiber membrane is not only a biofilm carrier, but also play the role of non-bubble aeration, oxygen and nutrients, respectively, come into the membrane from both sides of the biofilm.The study suggested that, MABR have a better removal efficiency on COD. The maximum COD removal rate is 85% at hydraulic retention time (HRT) of 24h,oxygen pressure of 0.5atm. The changes of PH, oxygen pressure, and flow rate have little effect on COD removal.