Fatigue Strength Reliability Analysis Of Spiral Bevel Gear Base On Monte Carlo Method

Spiral bevel gear is the most representative type in gear transmission. Spiral bevel gear is widely used in power transmission in the field of vehicles, railway locomotives, aviation navigation and mining energy. There are not usually the conditions of the large sample test on the gear products, so that the problem of reliability analysis and the lack of information evaluation is very outstanding. The reliability analysis and calculation method of spiral bevel gear fatigue strength which is based on Monte Carlo numerical simulation method is studied in this paper. The discussion of the prediction and evaluation method of the gear fatigue strength grey model is held. The main research contents and conclusions are as follows:1The methods of the stress-strength interference model used in the gear reliability analysis, and the Monte Carlo method used in MATLAB software are studied.2The distribution types of the random variable which affect the strength geometrical coefficient is assumpted. The random number group is generated based on MATLAB software programming, then the simulation of geometric coefficient is done by using Monte Carlo method, the distribution fitting test is completed and the analysis of the sensitivity of random factors is finished. It is proved that the geometric factor submits to the normal or lognormal distribution, and Monte Carlo simulation has high reliability.3Based on Monte Carlo method the numerical simulation on the contact stress and bending stress and their permissible stress have respectively been done. After obtaining the stress and strength results array, according to the stress and strengh interference model, the calculation of reliability is respectively done by using statistical method and numerical integral method. Finally, the sensitivity analysis are made on the stochastic factors influencing the fatigue strength distribution and the reliability.4The forecast evaluation of the small sample data of the gear fatigue life is studied by using the grey GM (1,1) model. The discussion of the feasibility of using grey system theory to predict the gear fatigue life test data is held. A new method is put forward for the prediction and the evaluation of the gear.fatigue life.In the actual working condition, the gear reliability is the result of the coupled action of many random factors. And the analysis is also a very complicated process, and only with the support of the test data, can it be more believable. The reliability analysis of the gear fatigue strength still needs a lot of research work.