【作者】 刘伟；

【导师】 屈福政；

【作者基本信息】 大连理工大学 ， 机械设计及理论， 2016， 硕士

【摘要】 柔性变幅门座起重机变幅机构失效时,臂架将失去平衡,可能造成事故。为避免此类事故发生,有的起重机加装了安全拉索。臂架折断的实际案例表明,这种解决方案的局限性还是非常明显的。为合理设置安全拉索,需要研究事故状态安全拉索作用过程中臂架的动力学性能。针对安全拉索方案的局限性,有人提出一种由双联变幅系统与常闭盘式安全制动器构成的另一种臂架安全系统代替安全拉索系统。为验证新安全系统的可行性,确定系统关键参数,对这种臂架安全系统作用过程中臂架动力学性能的研究是非常必要的。因变幅系统失效的臂架下落工况是非常危险的,所以不能通过试验的方法来研究安全系统的安全性,所以臂架安全系统的动力学仿真是解决安全系统参数设置问题的一个有效途径。本文以某采用安全拉索的柔性变幅门座起重机为研究对象。首先,以ADAMS为平台，结合ANSYS,建立安全拉索系统的刚柔耦合模型。通过对事故工况及最理想工况的仿真分析,结合仿真获得的臂架动力学性能,讨论不同工况下系统的安全性。其次,建立双联变幅系统与常闭盘式安全制动器构成的臂架安全系统的刚柔耦合模型,现场测试影响系统性能的关键参数,仿真分析了最危险工况,研究安全系统的可行性。然后,确定关键参数的研究范围,并对不同参数组合的新安全系统进行仿真,以臂架结构强度、变幅绳破断拉力和臂架极限仰角为限制条件,确定使新安全系统可行的关键参数有效范围。最后,任选关键参数有效范围内一点作为新安全系统的参数,并对该参数下新安全系统进行仿真,验证所得到的关键参数有效范围的正确性。研究结果表明：1.在事故状态下,即使安全拉索能为臂架提供足够的拉力,但臂架结构不足以承受安全拉索引起的冲击载荷,所以安全拉索不能保证臂架在事故状态下的安全；2.若能正确选取关键参数,双联变幅系统与常闭盘式安全制动器构成的臂架安全系统可行。本文的研究方法及结论为合理设置安全拉索和臂架变幅安全系统提供参考和借鉴。更多还原

【Abstract】 When luffing mechanism of flexible luffing portal slewing crane fails, the boom will be out of balance and it may cause an accident. In order to avoid similar accidents, some cranes to install a security cable. Actual boom broken case shows that the limitations of this solution is rather obvious. For setting up safety rope reasonably, dynamic behavior of the boom under the function of safety rope in accident condition is needed to study. In allusion to the limitation of safety rope, a new boom safety solution which consists of duplicate luffing system and normally closed disc type safety brake is proposed. In order to verify the feasibility of the new boom safety system and determine key parameters, the study of dynamics behavior of boom under the function of safety system is necessary.Boom drop caused by the failure of luffing system is very dangerous, so luffing system safety can’t be studied by test method. In this case, the dynamics simulation of boom safety system is the main basis to solve the problem of setting parameters of safety system.In this paper, a flexible luffing portal slewing crane using a safety rope is taken as the research object. The flexible multi-body dynamics simulation model of the safety rope systems is established by ADAMS and ANSYS. Firstly, dynamics simulations of crane under the accident condition and the ideal condition are carried on, based on the obtained dynamics behavior of boom, the system safety under different conditions is discussed. Secondly, the flexible multi-body dynamics simulation model of new boom safety system composed by duplicate luffing system and normally closed disc type safety brake is built, the key parameters affecting safety behavior are tested in field. The simulation and analysis under the most dangerous condition is carried on, and the feasibility of the safety system is studied. And then, determine the scope of the studying parameter, and new crane boom safety system under different parameters is simulated. Taking boom structure strength and luffing rope breaking force as limiting conditions, with reference to the boom limiting angle of elevation, effective parameter scope which can make new crane boom safety system feasible is got. Finally, taking one point of effective parameter scope as parameter of new crane boom safety system, and new crane boom safety system under the parameters is simulated. Also, the correctness of the parameter can be validated.The results show that:1. Under the accident conditions, even if the safety rope can offer enough tension force for the boom, but the boom structure can’t bear the impact loads caused by safety rope, so safety rope cannot ensure the safety of crane boom in accident conditions;2. If performance parameters are properly selected, new boom safety system composed by duplicate luffing system and normally closed disc type safety brake is feasible;Research methods and conclusions of this paper provide references for setting safety rope system and boom safety systems reasonably.更多还原