自平衡重载压力机以及油膜承载特性研究

发布时间：2018-01-11 10:22

本文关键词：自平衡重载压力机以及油膜承载特性研究　出处：《天津工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：重载压力机从开始的人工杠杆加载到现在液压加载与伺服反馈,可实现的功能越来越多,可观测的数据越来越丰富。但是目前,国内现有的重载压力试验机只能获得岩石的宏观力学特性和岩石试样破坏后的特性,例如岩石的变形,强度特性等。而岩石的动态破裂过程仍是个黑箱过程。那么岩石在大载荷的加载情况下,如何实现压力室平稳的旋转成为本次课题主要研究内容:本文首次提出了将液体油膜支撑技术运用于重载压力机,实现了在大载荷状况下压力室的平稳旋转。压力室中采用自平衡活塞的结构满足了试样上下表面围压的加载需求,使得岩石试样各种参数的准确性在测量时得到了很大的提高。本文以重载压力机加载油缸为研究对象,对垂向加载缸进行了动力学建模,在不忽略非线性摩擦力和非线性弹性力的情况下,通过MATLAB仿真研究对加载油缸动力学模型进行了分析,更具针对性地分析了重载压力机加载油缸低速爬行现象的原因。分析了油缸低速爬行现象影响因素中,非线性摩擦力泰勒展开各项系数中对低速振动现象的影响程度。有效的避免了加载油缸由于爬行现象引起的参数失真等状况,保证了试验的顺利进行。本文通过理论分析,基于液体油膜支承的实际问题提出流场简化模型,化简并求解流体连续性方程和运动方程,得到了速度、压强、承载力、油膜刚度等参数的解析解。采用有限元计算软件CFX对液体油膜支承系统进行了数值模拟计算,得出静态时液体油膜支承系统的流场分布。选出了油膜厚度在30μm时最为合适,保证了在大载荷的加载条件下压力室的平稳旋转。研究结果表明,本文所研究重载压力机在大载荷的情况下,基于液压油膜支撑的方案具有可行性。对于加载油缸低速振动现象的分析具有较高的理论价值和实践价值。
[Abstract]:Heavy press from the beginning to now, artificial loading loading and hydraulic servo feedback, more and more functions can be realized, the observed data is more and more abundant. But at present, the macro mechanical properties of rock and the existing domestic heavy pressure testing machine can only get the rock characteristics after the destruction of the test sample, such as rock deformation, strength characteristics. While the rock dynamic rupture process is still a black box process. Then the rock loading in large load, how to achieve the smooth rotation of the pressure chamber has become the main research contents of this paper: This paper firstly puts forward the liquid oil film supporting technology used in heavy-duty press, to achieve a smooth rotation in the large load under the condition of pressure chamber the structure of self balancing piston. Meet the specimen surface under the confining pressure loading demand pressure chamber, the rock samples of various parameters in the measurement accuracy when Has been greatly improved. Based on the heavy load cylinder press as the research object, the dynamic model of vertical loading cylinder, without neglecting the nonlinear friction and nonlinear elastic force, through the simulation of MATLAB dynamic model of load cylinder are analyzed, more targeted analysis of the reasons of heavy load cylinder press low speed creeping phenomenon. Analysis of the cylinder slow speed creeping factors, nonlinear friction Taylor influence on the phenomenon of the low speed vibration coefficient. Avoid loading cylinder parameters due to creeping phenomenon of distortion caused by other conditions, to ensure the smooth progress of the pilot. In this paper, through theoretical analysis, the actual problems of liquid oil film bearing the flow field is proposed based on the simplified model, simplify and solve the fluid continuity equation and motion equation, the velocity, pressure, bearing Force analysis of the oil film stiffness and other parameters of the solution. Using the finite element software CFX on the liquid oil film bearing system are simulated, the flow field distribution of static liquid oil film bearing system was selected. The oil film thickness of 30 m when the most appropriate, to ensure the smooth rotation in loading conditions the load under the pressure chamber. The results show that, the study of heavy press in load, hydraulic oil film supporting scheme based on the feasibility analysis for the loading cylinder. With high low speed vibration phenomenon of the theoretical value and practical value.

【学位授予单位】：天津工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE93

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