扭矩轴类零件有限元分析方法探讨

分别采用ANSYS和Simulation对某扭矩轴产品进行有限元分析,将两个软件得到的应力分析结果与实际使用情况进行对比分析,目的在于探索此类分析的最佳方法,对比结果显示,采用Simulation对扭矩轴类产品进行有限元分析具有操作简便、准确性高的特点,研究可为扭矩轴类零件的设计提供有效的技术支持。

大转矩复合材料推力轴设计与分析

介绍了复合材料轴在船舶应用上的优点和国内外发展现状,提出了大转矩复合材料推力轴设计方案并进行有限元建模。通过对大转矩复合材料推力轴设计方案的强度和模态进行分析,结果显示该设计方案满足大转矩复合材料推力轴额定工况强度要求和屈曲强度要求,其一阶临界转速也满足方案设计许用转速的要求。

EFFECTS OF MANUFACTURING ERRORS ON GAS LUBRICATED JOURNAL BEARING WITH COMPLIANT SURFACE

A theoretical study has been performed to investigate the influence of manufacturing errors on the bearing housing of a gas lubricated journal bearing with compliant surface I in particular on the bearing load capacity. A gas film thickness distribution is presented, in which errors o f both circumferential and axial bearing housing are considered. The influence of the errors on bearing performance is compared between rigid and compliant surface bearings. It was shown that the compliant surface bearings are less sensitive to the manufacturing errors than the rigid surface bearings. Thelefore, the cost of compliant surface bearing could be reduced by setting a larger manufacturing error tolerance.

Finite element analysis of deformation characteristics in cold helical rolling of bearing steel-balls

Due to the complexity of investigating deformation mechanisms in helical rolling(HR) process with traditional analytical method, it is significant to develop a 3D finite element(FE) model of HR process. The key forming conditions of cold HR of bearing steel-balls were detailedly described. Then, by taking steel-ball rolling elements of the B7008 C angular contact ball bearing as an example, a completed 3D elastic-plastic FE model of cold HR forming process was established under SIMUFACT software environment. Furthermore, the deformation characteristics in HR process were discovered, including the forming process, evolution and distribution laws of strain, stress and damage based on Lemaitre relative damage model. The results reveal that the central loosening and cavity defects in HR process may have a combined effect of large negative hydrostatic pressure(positive mean stress)caused by multi-dimensional tensile stresses, high level transverse tensile stress, and circular-alternating shear stress in cross section.

Axial Compression Behavior and Analytical Method of L-Shaped Column Composed of Concrete-Filled Square Steel Tubes

Based on the characteristics of an L-shaped column composed of concrete-filled square steel tubes, the axial compression experiment and nonlinear finite element analysis were carried out to study the mechanical property of the L-shaped column. The load-displacement curve for the L-shaped column, the deflection and load-strain curves for the mono columns were obtained by the axial compression experiment. The results show that the L-shaped column exhibits a flexural-torsional buckling failure mode. The numerical simulation by the finite element analysis shows that the bearing capacity and failure mode are in accordance with those of the axial compression experiment and the feasi- bility of the finite element analysis is proved. For the calculation of the bearing capacity of the L-shaped column com- posed of concrete-filled square steel tubes, an analytical method is proposed based on the theory of the elastic stability and spatial truss model. The results of the analytical method are in good agreement with those of the axial compression experiment and the finite element analysis.

Finite element analysis of effect of soil displacement on bearing capacity of single friction pile

Effect of soil displacement on friction single pile in the cases of tunneling,surcharge load and uniform soil movement was discussed in details with finite element method.Lateral displacement of the pile caused by soil displacement reached about 90% of the total displacement,which means that P-Δ effect of axial load can be neglected.The maximum moment of pile decreased from 159 kN·m to 133 kN·m in the case of surcharge load when the axial load increased from 0 to the ultimate load.When deformation of pile caused by soil displacement is large,axial load applied on pile-head plays the role of reducing the maximum bending moment in concrete pile to some extent.When pile is on one side of the tunnel,soil displacements around the pile are all alike,which means that the soil pressures around the pile do not decrease during tunneling.Therefore,Q-s curve of the pile affected by tunneling is very close to that of pile in static loading test.Bearing capacities of piles influenced by surcharge load and uniform soil movement are 2480 kN and 2630 kN,respectively,which are a little greater than that of the pile in static loading test(2400 kN).Soil pressures along pile increase due to surcharge load and uniform soil movement,and so do the shaft resistances along pile,as a result,when rebars in concrete piles are enough,bearing capacity of pile affected by soil displacement increases compared with that of pile in static loading test.

Finite element analysis of couple effect of soil displacement and axial load on single inclined pile

The couple effect of soil displacement and axial load on the single inclined pile in cases of surcharge load and uniform soil movement is discussed in detail with the methods of full-scale field tests and finite element method. Parametric analyses including the degree of inclination and the distance between soil and pile are carried out herein. When the displacement of soil on the left side and right side of a pile is identical, deformation of a vertical pile and an inclined pile is highly close in both cases of surcharge load and uniform soil movement. When the couple effect of soil displacement and axial load occurs, settlement of an inclined pile is greater than that of a vertical pile under the same axial load, and bearing capacity of an inclined pile is smaller than that of a vertical pile. This is quite different from the case when the inclined pile is not affected by soil displacement. For inclined piles, P-Δ effect of axial load would lead to a large increase in bending moment, however, for the vertical pile, P-Δ effect of axial load can be neglected. Although the direction of inclination of piles is reverse, deformation of piles caused by uniform soil movement is totally the same. For the inclined piles discussed herein, bending moment(-8 m to-17 m under the ground) relies heavily on uniform soil movement and does not change during the process of applying axial load. When the thickness of soil is less than the pile length, the greater the thickness of soil, the larger the bending moment at lower part of the inclined pile. When the thickness of soil is larger than the pile length, bending moment at lower part of the inclined pile is zero.

SOLUTION TO THE STRESS DISTRIBUTION ON THE SURFACE LAYER OF BUSHING ALLOY BY COUPLING BEM WITH ELASTICITY METHOD

In the design of the fatigue strength of dynamically loaded bearing in the equipmentssuch as internal combustion engines and roimg mun, the solution to the stress distribution on thebushing alloy layer is an important and difficult problem. In this paper, a new method has beenproposed by coupling BEM with etheticity method, The algorithm and its implementation were deseribed in details The calculation results verify that this up-dated method can provide us a moresimple and effective tool for solvingthe fatigue stress of the bushing alloy with tangible benefit oftime-saving and high computation accuraey. It may open a new vista in bearing fatigue strength design.