节点文献
盾构推进系统的分区建模与性能评价
Modeling and Performance Assessment for the Grouping of the Thrust System of the Shield Machine
【作者】 邓颖聪;
【导师】 郭为忠;
【作者基本信息】 上海交通大学 , 机械设计及理论, 2010, 硕士
【摘要】 盾构是现代化的隧道施工装备,而推进系统是盾构的关键组成部分,主要承担着整个盾构的顶进任务。推进系统应能完成盾构的转弯、曲线行进、姿态控制、纠偏以及同步运动等,对推进系统进行分区控制是实现盾构有效推进作业的核心手段。随着经济的快速发展和城市化进程的加快,我国对盾构的需求急剧增加,对掌握盾构的设计理论的要求也越来越迫切。本文对盾构推进系统的分区、运行机理开展研究,取得如下成果:1、盾构推进系统等效机构模型建立盾构推进系统由为数众多的油缸沿环向均匀布置,每个推进缸前端铰接,后端通过顶靴顶在衬砌上。将顶靴与管片的接触部位等效为球副连接,将一条油缸支链等效为一条SPS支链,整个推进系统等效为具有多条SPS支链的并联机构。推进系统被分区后,根据力和力矩合成原理,一个分区的所有油缸可以简化为一条SPS支链,进而可以建立推进系统的分区等效机构模型。2、推进系统油缸分区的分区型式提出盾构推进系统所需克服的主要载荷是盾体与土体的摩擦力,其摩擦力的分布左右对称、上下非对称,为使推进系统有较好的土体顺应性,推进系统的油缸分区布置应与推进载荷分布相匹配。分区应遵循左右对称的原则,依照该种原则,本文提出了8种可能的分区型式,以供设计者选型。3、推进系统性能分析基于推进系统的等效机构模型,利用并联机构的反解方法,对推进系统进行了位置分析、速度分析、静力平衡分析。在求解静力平衡方程时,又提出了处于奇异位形邻域的驱动冗余并联机构静力求解的分割求解算法。4、推进系统分区性能评价指标建立推进油缸直接作用在管片上,管片往往承受到较大的推进反力,推进力的分布不均将使管片受力不均,会影响管片的拼装效果,使管片脱臼,甚至断裂。基于此,提出了推进力均匀性评价指标,用来对推进系统油缸分区进行性能评价。
【Abstract】 The Shield Machine is the modern equipment for tunnel construction, and the thrust system is the key part of the shield machine. The thrust system mainly undertakes the advances of the shield machine. The thrust system should be able to turn around, advance along a designed line, control the pose, correct error, move synchronizedly, and so on. The grouping-oriented control of the thrust system is the core method to advance the shield machine. With the rapid growing of the economy and urbanization, the quantity demand of the shield machine will greatly increase, thus mastering the design theory of the shield machine is exigent. This paper researches the mechanisms of grouping and advancing of the shield machine, the content is listed in the following:1. Equivalent mechanism modeling for the thrust system of the shield machine.The thrust system consists of many hydraulic cylinders distributed in the circular direction. Each cylinder is articulated to the fore part of the shield machine in one end, with another end pressing against the segment by a shoe. The part that the shoe touches the segment is regarded as a spherical pair, and then each cylinder with its two ends is regarded as one SPS leg. So the whole system can be equivalent to a parallel mechanism with many SPS legs. When the thrust hydraulic cylinders are divided into several groups, one group can be simplified to one SPS leg in terms of the composition principle of the forces and the moments. Therefore, the equivalent mechanism of the grouped thrust system can be modeled.2. Proposition of the grouping types for the thrust system.The main load acting on the thrust system is the friction between the shield and the earth. The distribution of the friction is bilateral symmetry. The distribution of the groups of the thrust hydraulic cylinders should comply with the distribution of the load, so that the thrust system will have better compliance. So the groups should also be bilateral symmetry. According to this principle, 8 possible grouping types are proposed for the designer to choose, and the equivalent models of different grouping types are modeled.3. Performance analysis for the thrust system.Based on the equivalent mechanism, position, velocity, statics are analyzed by the inverse method of the parallel mechanism. For sovling the equation of balanced statics when the redundant mechanism is singular, a dividing method is proposed.4. Evaluting indicator for performance analysis of different grouping models.Thrust hydraulic cylinders touches directly to the segments, the reaction force of the thrust force acts on the segments. Since the reaction force is always very large, the uniformity of the reaction force will affect the segments. Bad uniformity of the reaction force will dislocate the segments, even destroy the segments. Based on this, the evaluating indicator of the uniformity of the thrust force is proposed to evaluate different grouping models.
【Key words】 Shield Machine; Thrust Machine; Grouping; Equivalent Mechanism Modeling; Performance Evaluating;