某款齿轮齿条式动力转向器齿轮断裂分析

某款齿轮齿条式动力转向器配套车型在行驶3770公里时,齿轮发生了断裂。为查清断裂原因,采用光谱仪、光学显微镜、硬度计等手段对其进行了检测,并建立模型使用CAE软件对其进行强度分析。发现该齿轮断裂是由于设计强度较低,经CAE分析受力薄弱环节和断裂零部件位置相吻合。通过增加该款齿轮齿条动力转向器齿轮薄弱环节的直径,提高齿轮强度,解决了断裂问题。     

水泥混凝土路面板下脱空的危害

通过对多处水泥混凝土路面板下脱空形态的试验研究 ,获得脱空区的形态分布规律 ,并据此对不同车辆荷载作用下板体内应力变化进行解析求解和使用寿命计算。结果表明 ,水泥混凝土路面板下脱空、超载车辆和重载车辆是造成水泥混凝土路面板早期断裂的重要因素     

Quasi-non-linear fracture mechanics analysis of splitting failure in moment-resisting dowel joints

This article addresses the splitting failure of moment-resisting dowel-type fastener joints, in which the failure may be attributed to the perpendicular-to-grain loading of one single dowel located close to the end of a beam. A quasi-non-linear fracture mechanics model based on beam on elastic foundation theory is applied. A simple approximation suitable for practical design is also proposed. Model predictions of the influence of edge distances and end distances are compared with test results.     

基于随机有限元法的木材断裂参数的研究

引用简化的罚函数本构方程，完成幂律非线性随机有限元方法，将随机有限元方法引入木材断裂力学。考虑到裂纹尺寸的随机性，根据J积分的变化率以及J—K的关系计算出木材强度因子的变化曲线。为验证其可行性．进行相关实验，木材强度因子的测试曲线具有相同的变化趋势，误差在同一个标准差内，从而证明采用随机有限元方法对木材的断裂特性进行计算和预测是可行和适用的。     

RESERCH ON THE COLD START OF 200MW CHINESS-BUILT STEAM TURBINES

In this paper, the temperature field, stress, critical crack size and expenditure rate of life of HP and IP rotors of 200MW Chinese-built steam turbines in eight typital patterns of cold start of Chongqing Power Plant was calculated by finite element method. Some problems in speed-up process have been discussed, and advanced that it is better to appraise start-up process by Fracture Mechanics Mechod in the period when the temperature of rotor is low. The discussion are useful for the start of steam turbines.     

Fracture Analysis of Tense Bolt

In this methods of fracture mechanics and reliability are used toanalyse the causes for failure of a flange bolt connecting an inclinded rope to the natural gas pipelinebridge spaning the Changjiang(the Yangtze River)loeated at Chongqing and the proper safetymeasures that should be required are propozed.     

Frequency Hydraulic Aperture about Fracture Seepage in Rock Mass

The frequency aperture given in this paper is a new method that describes the fracture aperture composition. The aperture curve plays a role in describing the aperture distribution and uniformity. In particular, the frequency hydraulic aperture is of great importance in seepage analysis. It overcomes limitations of hydraulic aperture and mean aperture. Based on existing information, the result of example calculation shows that the hydraulic aperture e h equals to the median aperture e 50 . This paper also obtains that the frequency hydraulic aperture e sh equals to e 48 through finite element numerical modeling for various type of random fracture.     

STUDY ON DEVELOPMENTAL BEHAVIOUR AND DEFORMATIONAL FRACTURE MECHANISM OF SHIJIANG SLIDE IN CHONGQING

In this paper,the geological background as well as thedevelopment characteristics,deformation rupture behavior,and slideformation mechanics of the old and new slide area and the creeping rupturezone of Chongqing Shijialiang Landslide are analyzed in full detail.Onthe basis of this,the forecasting comment on the stability of the slide ismade and the protection measures are suggested.