井下凿岩用钎杆动力学分析

发布时间：2018-04-10 00:05

本文选题：凿岩用钎杆　切入点：入射应力　出处：《辽宁科技大学》2015年硕士论文

【摘要】：钎杆是井下凿岩工作中消耗量最大的零件,是重要的“传力系统”,其工作性能和使用寿命一直是人们最关注的性能指标。钎杆的工作状态极其复杂,在恶劣的环境下,既要受到活塞的高频高强度冲击,又要承受凿岩机施加的扭矩,还要抵抗各类岩石的抗力及矿水的腐蚀。若凿岩机的冲击频率与钎杆的固有频率相同或接近,则会产生共振现象,在钎杆的径向产生很大的变形;钎杆受到瞬间的冲击作用又使得钎杆纵向产生极大的拉压应力。这些都极易影响钎杆的使用寿命和性能,尤其是在共振和高强度冲击同时发生的时候。为了解决这些问题,本论文主要研究工作如下:(1)从理论上分析了凿岩机活塞碰撞钎杆瞬间,应力波在活塞中传播及在钎杆与活塞接触面处的透射、反射的过程以及凿岩机钎杆入射应力波形的影响因素。以YGZ-90型凿岩机为例,根据钎杆与活塞碰撞时应力波的透射与反射规律,计算该型凿岩机在匹配H35中空六角螺纹连接钎杆时的钎杆入射应力波随时间变化的关系。(2)以ANSYS为平台,从共振的观点分析了钎杆的动力学特性,以长度为2105mm的钎杆为例,通过有限元模态分析得到其前六阶固有频率及其相对应的振型;对不同长度的凿岩用中空六角螺纹连接钎杆进行了模态分析,得到了不同长度钎杆的固有频率,及钎杆长度对钎杆各阶固有频率的影响。通过谐响应分析得出了钎杆在危险频率下的响应及一些响应峰值,并得到了各阶固有频率对钎杆的影响程度。为凿岩机冲击频率与钎杆固有频率的匹配,在实际凿岩工作中避免共振现象的发生提供了一定依据。(3)从动力学的角度分析其断裂的原因。以LS-DYNA仿真软件为平台,对长度为2105mm的H35中空六角螺纹连接钎杆在匹配YGZ-90凿岩机时进行冲击动力学仿真,分析了钎杆两种极端工作状态下(固定端反射和自由端反射)受到双圆柱活塞单次冲击后的应力波的产生和应力波在钎杆中传播、反射的过程,及应力波所到达之处的应力分布,得出了钎杆在凿钻过程中最容易发生失效的部位。通过分析钎杆各个位置的应力分布和现场采样对比分析,验证了仿真分析结果与现场实际基本相符,证明对钎杆进行的动力学分析是可行的。
[Abstract]:Drill rod is the most consumed part in rock drilling and an important "force transfer system". Its working performance and service life have been the most concerned performance index.The working condition of the drill rod is extremely complex. Under the harsh environment, it is not only subject to the high frequency and high strength impact of the piston, but also to the torque of the rock drill, and also to resist the resistance of all kinds of rock and the corrosion of the mineral water.If the impact frequency of the drill is the same or close to the natural frequency of the drill rod, resonance will occur, which will cause great deformation in the radial direction of the drill rod, and the rod will be subjected to the impact of the moment and the longitudinal tension and compression stress of the drill rod will be greatly produced.These can easily affect the service life and performance of drill rod, especially when resonance and high strength impact occur at the same time.In order to solve these problems, the main research work of this paper is as follows: 1) theoretically, the stress wave propagates in the piston and the transmission at the interface between the drill rod and the piston is analyzed theoretically.The process of reflection and the influence factors of the incident stress waveform of drill rod.Taking YGZ-90 type rock drill as an example, according to the transmission and reflection law of stress wave during the impact of drill rod and piston, this paper calculates the relation of incident stress wave of drill rod with H35 hollow hexagonal thread connecting rod with time when the drill rod is connected with H35 hollow hexagonal thread according to the law of transmission and reflection of stress wave during the collision of drill rod and piston.The dynamic characteristics of drill rod are analyzed from the viewpoint of resonance. Taking the drill rod with length of 2105mm as an example, the first six natural frequencies and their corresponding modes are obtained by finite element modal analysis.The modal analysis of drill rod with hollow hexagonal thread for rock drilling of different lengths is carried out. The natural frequency of drill rod with different length and the influence of drill rod length on the natural frequency of drill rod are obtained.Through harmonic response analysis, the response of drill rod under dangerous frequency and some response peaks are obtained, and the influence of various natural frequencies on drill rod is obtained.This paper provides a certain basis for matching the impact frequency of rock drill with the natural frequency of drill rod and avoiding the occurrence of resonance in actual rock drilling.On the platform of LS-DYNA simulation software, the impact dynamics of H35 H35 hollow hexagonal thread connecting rod in matching YGZ-90 rock drill is simulated.The stress wave generation and the process of stress wave propagating and reflecting in drill rod under two extreme working conditions (fixed end reflection and free end reflection) under single impact of double cylindrical piston are analyzed.The stress distribution of the drill rod is obtained, which is the most prone to failure in the drilling process.By analyzing the stress distribution of the drill rod at each position and the field sampling and contrast analysis, it is verified that the simulation results are basically consistent with the field practice, and it is proved that the dynamic analysis of the drill rod is feasible.
【学位授予单位】：辽宁科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD421.2

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