基于虚拟样机的四索式抓斗改进与仿真研究

发布时间：2018-08-27 11:08

【摘要】：桥式抓斗卸船机是港口码头上应用最广泛的起重设备,抓斗作为桥式抓斗卸船机的核心机构,凭借着它种类广泛、灵活性强及可靠性高等优势,被广泛的用于物料的抓取工作。但是在传统的机械设计工作中,设计人员为了保证抓斗具有足够的安全性和可靠性,人为的将设计抓斗的安全系数加大,使得抓斗机构的尺寸厚大笨重,不仅浪费钢铁资源,也使得抓斗的抓取效率降低。因此对抓斗进行基于强度和刚度及满足实际使用要求下的轻量化具有重要的实际意义。为了对抓斗进行基于强度和刚度及满足使用要求下的轻量化研究,以25t长撑杆四索双瓣抓斗为例,首先,对抓斗进行传统设计下的分析,根据抓斗的理论提升量来估算出抓斗的理论质量,再根据抓斗自重分配系数对抓斗各部分进行了重量分配;其次,对25t抓斗建立三维模型,分析抓斗模型的自重及其各部分自重大小,对比理论抓斗设计量,证明抓斗模型与理论抓斗模型相符合;然后对抓斗模型进行静力学分析和模态分析,证明原抓斗模型的满足刚强度要求,接着对抓斗提出了四种改进方案,分别对抓斗的撑杆和斗体尺寸进行减少,对改进的抓斗模型进行静力学分析,对比四种改进方案,提出对抓斗的改进方案,即将抓斗撑杆厚度减少6mm,斗体厚度减少3mm;最后,对抓斗的最终改进方案进行疲劳分析以及在三种非正常工况下的安全性分析,证明了抓斗改进方案具有很高的可靠性,确定了最终的改进方案,即将抓斗撑杆处厚度减少6mm,斗体处厚度减少3mm,此时抓斗质量减少了约704kg。通过对抓斗进行一系列的仿真研究,确定了抓斗的最终改进方案,使得抓斗的质量减少了,也验证了抓斗改进模型的可靠性,为同类抓斗的轻量化提供了一个研究思路。
[Abstract]:Bridge grab ship unloader is the most widely used lifting equipment in port wharf. As the core mechanism of bridge grab ship unloader, grab bucket is widely used in material grabbing work by virtue of its wide variety, strong flexibility and high reliability. However, in the traditional mechanical design work, in order to ensure sufficient safety and reliability of the grab, the designer artificially increases the safety factor of the design grab, which makes the size of the grab mechanism large and heavy, which not only wastes iron and steel resources, It also reduces the grab efficiency of grab bucket. Therefore, it is of great practical significance to lighten the grab based on strength and stiffness and meet the requirements of practical use. In order to study the lightweight of grab based on strength and stiffness and meet the requirement of application, taking 25t long support bar four cable double flap grab as an example, firstly, the traditional design analysis of grab bucket is carried out. According to the theoretical lifting quantity of grab, the theoretical quality of grab is estimated, and the weight distribution of each part of grab is carried out according to the coefficient of gravity distribution of grab. Secondly, the 3D model of 25t grab is established. By analyzing the gravity of grab model and the weight of each part, comparing the design quantity of theoretical grab, it is proved that the grab model is consistent with the theoretical grab model, and then the static analysis and modal analysis of grab model are carried out. It is proved that the original grab model meets the requirements of rigid strength, and then four improved schemes are put forward to improve the grab bucket. The dimensions of the brace and the bucket body are reduced respectively. The static analysis of the improved grab model is carried out, and the four improved schemes are compared. The improvement scheme of grab is put forward, that is, the thickness of grab pole is reduced by 6 mm, and the thickness of bucket is reduced by 3 mm. Finally, the fatigue analysis and safety analysis of the final improvement scheme of grab are carried out under three kinds of abnormal working conditions. It is proved that the improvement scheme of grab bucket has high reliability, and the final improvement scheme is determined, that is, the thickness of grab pole is reduced by 6 mm and the thickness of bucket body is reduced by 3 mm, and the grab mass is reduced by 704 kg. Through a series of simulation studies on grab, the final improvement scheme of grab is determined, which reduces the quality of grab and verifies the reliability of the improved model of grab, which provides a research idea for the lightweight of similar grab.
【学位授予单位】：华北理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U653.928.1

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