共查询到20条相似文献,搜索用时 0 毫秒
1.
2.
3.
4.
根据金属疲劳裂纹扩展理论,对机械零件断裂疲劳强度可靠性进行了探讨,提出了一种新的疲劳寿命可靠性预测与设计方法。 相似文献
5.
The fundamental problem of the power control for the driving of a dual-motor drive electric tracked vehicle is analyzed. The tracked vehicle and its electric drive system are mathematically modeled. Power control schemes of the dual-motor drive system is put forward, designed, and analyzed, including the distributed control system and the two control schemes speed-regulation and torque-regulation. The field experiment shows that the two types of drive control schemes realize the driving function of the vehicle feasibly and effectively. Obviously the comprehensive controller and two motors’ controllers are closely coupled in the “speed-regulation” control scheme, in which they must coordinate very well to guarantee the control. Contrastingly, in the “torque-regulation” control scheme, the comprehensive controller and two motors’ controller are not dependent closely when the accuracy and response of the torque controlling is guaranteed. The latter is simpler and more practical than the former. 相似文献
6.
重点介绍利用断裂力学理论进行门式起重机结构的疲劳寿命分析的方法,通过运用损伤容限设计方法对门架结构进行的疲劳寿命计算,得出了门机主梁与悬臂梁联结部位初始裂纹为0.5mm时门架结构的设计寿命,并分析了模型中参数变化对门架结构寿命的影响,说明利用该方法估算门架结构的寿命具有可行性,对实际工程具有参考价值。 相似文献
7.
8.
Paris law can reflect the failure mechanism of materials and is usually used to be a method to predict fatigue life or residual fatigue life.But the variable which can represent the health of machine i... 相似文献
9.
以三菱重工为代表的日本大型起重机结构设计技术在全球技术市场具有鲜明的技术特色和领先优势,其核心技术之一是基于应力幅法为基础的结构疲劳寿命设计与评估技术。我国最新的起重机设计规范提到了这一技术,但由于存在一些基础性技术数据和实践的空白,未能启动这一技术的应用。为破解这一技术的核心竞争力,通过关注和跟踪三菱重工起重机结构疲劳寿命设计技术,对其在中国应用的多台产品进行了结构疲劳计算和疲劳试验。本文以1台440t铸造起重机为例,分析了这项技术应用于冶金起重机领域的特色和实用性。 相似文献
10.
Shang De-guang Sun Guo-qin Deng Jing Yan Chu-liang 《Frontiers of Mechanical Engineering in China》2006,1(3):265-269
On the basis of the continuum fatigue damage theory, a nonlinear uniaxial fatigue cumulative damage model is first proposed.
In order to describe multiaxial fatigue damage characteristics, a nonlinear multiaxial fatigue cumulative damage model is
developed based on the critical plane approach. The proposed model can consider the multiaxial fatigue limit, mean hydrostatic
pressure and the unseparated characteristic for the damage variables and loading parameters. The recurrence formula of fatigue
damage model was derived under multilevel loading, which is used to predict multiaxial fatigue life. The results showed that
the proposed nonlinear multiaxial fatigue cumulative damage model is better than Miner’s rule. 相似文献
11.
焊接结构虚拟疲劳试验技术研究 总被引:2,自引:0,他引:2
针对焊接结构的疲劳问题,提出虚拟疲劳试验技术.基于有限元数值仿真技术及焊接接头S-N曲线数据库,在计算机中模拟物理样机的疲劳试验过程,预测焊接结构的疲劳寿命,使产品在设计阶段开展抗疲劳设计成为可能.虚拟疲劳试验在铁路车辆焊接摇枕上的应用验证了该技术的可行性. 相似文献
12.
Behaviour of a series of lubricant oils and the effect of a non stoichiometric inorganic compound, as solid extreme pressure additive, on rolling fatigue life are studied using the rolling four-ball accelerated service simulation test proposed by Barwell and Scott. The results show, in all tested cases, the remarkable efficacy of this type of additive. The Total Acidity Number (tan) was found to increase with performance time for the case of the base lubricant, while for the oils with additives, it remained at its constant low value. This led to a proposal of a possible mechanism of the additive performance in the rolling process. 相似文献
13.
14.
15.
16.
Pan JIA Huaiju LIU Caichao ZHU Wei WU Guocheng LU 《Frontiers of Mechanical Engineering》2020,15(1):123
Rolling contact fatigue (RCF) issues, such as pitting, might occur on bevel gears because load fluctuation induces considerable subsurface stress amplitudes. Such issues can dramatically affect the service life of associated machines. An accurate geometry model of a hypoid gear utilized in the main reducer of a heavy-duty vehicle is developed in this study with the commercial gear design software MASTA. Multiaxial stress–strain states are simulated with the finite element method, and the RCF life is predicted using the Brown–Miller–Morrow fatigue criterion. The patterns of fatigue life on the tooth surface are simulated under various loading levels, and the RCF S–N curve is numerically generated. Moreover, a typical torque–time history on the driven axle is described, followed by the construction of program load spectrum with the rain flow method and the Goodman mean stress equation. The effects of various fatigue damage accumulation rules on fatigue life are compared and discussed in detail. Predicted results reveal that the Miner linear rule provides the most optimistic result among the three selected rules, and the Manson bilinear rule produces the most conservative result. 相似文献
17.
Propagation in fretting fatigue from a surface defect 总被引:3,自引:0,他引:3
This paper analyses the growth of cracks in fretting fatigue from an initial flaw at the surface. Different crack growth laws are used in order to take into consideration the particular behaviour of short cracks. This methodology is applied to estimate life in various fretting fatigue tests with spherical contact characterized by two different geometries. The material used in the experiments is Al7075. The two geometries present significant differences in the evolution of the stresses, crack growth, etc. which are discussed. The approaches used to model short crack growth give different results, some of them being in good agreement with the experiments. 相似文献
18.
以某180 t×24.85 m冶金桥式起重机为对象,应用有限元分析软件Ansys研究桥架的变形和应力分布状态,并与现场测试结果进行对比分析。结果表明,该起重机的最大挠度、静态Von Mises等效应力和第一阶固有频率均符合起重机设计规范要求。通过无损探伤发现桥架北主梁的下盖板上有裂纹,应用有限元分析和损伤容限设计对起重机裂纹的疲劳寿命进行研究,其分析数据可为起重机的日常维护检修和安全评估提供参考。 相似文献
19.
In this paper, as the second part of another previously published in this journal, the behaviour of a non-stoichiometric inorganic compound (nsic-bp1 additive) in a water-accelerated rolling fatigue test is studied.The results show the remarkable efficacy of the additive against the detrimental action of water present in lubricating oil. The efficacy of additive to inhibit the pernicious effect of water is explained by its reaction capacity. 相似文献
20.
以疲劳寿命分析理论成果为指导,对大型水陆两栖飞机主起落架进行疲劳寿命计算分析与结构优化研究。通过Hypermesh进行模型有限元前处理,在NASTRAN中计算应力分布结果,利用NcodeDesignlife研究起落架整体结构件疲劳寿命;通过LMS Virtual.Lab建立前起落架刚柔耦合模型,得到各个零部件连接部位节点力,从而完成对各个零部件的独立建模分析计算;基于疲劳寿命的结构优化技术,以Optistruct为工具对起落架疲劳寿命薄弱部位进行形状优化,使得疲劳寿命进一步提高。 相似文献