液压挖掘机工作装置的动力学仿真

在Catia软件中建立挖掘机工作装置的三维模型,基于机械系统动力学自动分析(ADAMS)软件,建立虚拟样机模型,并进行动力学仿真分析.对油缸添加Step函数,实现挖掘机虚拟样机在典型姿态下的挖掘过程仿真,考察挖掘机在某些工况下的挖掘性能,进一步得出动臂、斗杆、铲斗等构件各铰接点处的受力情况及响应曲线.同时,对挖掘机油缸在额定液压下的最大铲斗挖掘力进行校核.研究表明,所测挖掘机工作装置各铰接点的受力情况符合挖掘实际工况.     

基于虚功原理和Pro/E的六杆机构仿真分析

为了提高压床六杆机构的运动学和动力学仿真分析效率,运用Pro/E骨架模型建立压床六杆机构的运动学模型并对其进行运动学仿真,得出压床冲头的位移、速度和加速度随主动件转角变化的规律曲线.利用虚功原理结合MATLAB语言求解出主动件的平衡力矩,并得到机构的动能、驱动功和阻力功的变化规律.该分析方法可将设计者从复杂的矢量解析法、矩阵运算以及动力学分析软件中解放出来,从而提高六杆机构的分析效率.     

挖掘装载机的整机参数化建模及仿真研究

将虚拟样机技术与ADAMS软件相结合,建立了挖掘装载机WZ30-25的整机参数化模型;介绍了ADAMS中的驱动约束函数,仿真测量了液压挖掘装载机WZ30-25仿真模型的各种技术参数;最后,通过模型预测了挖掘装载机的工作性能。虚拟样机技术的研究范围主要是机械系统运动学和动力学分析,其核心是利用计算机辅助分析技术进行机械系统的运动学和动力学分析。与传统CAD方法相比,它提高了设计速度和设计质量并降低成本。这种基于虚拟样机模型的参数化建模,对于装载机工作装置的设计研究具有普遍的适用性。     

8t液压挖掘机工作装置的运动仿真

使用Creo2.0软件对挖掘机工作装置进行三维建模,基于动力学分析软件ADAMS2016建立虚拟样机,并进行运动仿真,设计相关的step函数,实现挖掘机工作装置某些特殊工况,进一步得出整个工作装置的轨迹包络图,从而获得一些重要工作参数如最大挖掘半径、最大挖掘深度、最大卸载高度等.同时建立工作装置的数学模型,并通过MATLAB软件进行编程计算,来探索挖掘机的工作性能及运动规律.仿真所得的数据可以为后期优化改进提供理论依据和设计参考.     

挖掘机工作装置运动学仿真

以日立EX200LC-5型反铲液压挖掘机为对象,采用proe建立液压挖掘机的工作装置虚拟模型,采用Adams软件进行运动学仿真,模拟挖掘机正常工作状态.运用运动学仿真结果计算最大挖掘半径、最大挖掘深度、最大挖掘高度与已有的20t日立挖掘机参数进行比对,两者结果吻合较好.对挖掘机工作装置进行优化,使工作装置最大挖掘半径变大,其工作更有效率.     

轿车与行人碰撞事故重建研究

基于多刚体动力学软件PC-Crash,对一起实际发生的轿车与行人碰撞事故进行重建,分析碰撞后行人的运动学响应过程及损伤部位的动力学响应参数,将仿真中得到的行人运动学响应及损伤部位的动力学响应结果与法医尸体检验报告中的客观事实进行对比,验证PC-Crash重建模型的可靠性,得到了仿真结果与客观事实相吻合的结论.结果表明,利用PC-Crash软件对实际案例快速重建,对于研究交通事故中行人损伤机理和鉴定事故责任具有重要的参考价值.     

2-DOF模拟台姿态误差动力学仿真分析

针对并联运动模拟台普遍存在的铰链间隙误差、结构误差和装配误差等问题,提出了一种误差模型建模简便且姿态误差仿真结果真实度高的方法。首先采用闭环矢量法建立模拟台的误差运动学模型,应用仿真软件Adams建立模拟台的误差动力学模型;然后对以上两种建模方法得到的误差模型进行仿真分析。通过对比,误差动力学仿真曲线优于传统运动学仿真结果。最后,采用方差指标进行评价分析。结果表明,误差动力学仿真分析能够更加真实反映模拟台的姿态变化,并且模拟台方位轴对间隙误差更为敏感。     

小型液压挖掘机工作装置虚拟样机的仿真与分析

利用PRO/E软件建立液压挖掘机工作装置的三维实体模型,并导入到ADAMS中,添加约束建立虚拟样机。计算各个油缸位移的step函数、铲斗齿尖受力的step函数和物料重力的step函数,并进行动力学仿真,得到几个主要铰接点处的受力曲线,为液压挖掘机工作装置的强度分析和结构优化提供了依据。运用模拟测力计的原理,对虚拟样机斗杆油缸的最大挖掘力进行仿真测试。计算出斗杆油缸的最大挖掘力,将计算结果与仿真结果进行了对比分析,为挖掘机挖掘力的测试提供了一条新途径。     

BH-1型月球车的运动学和动力学研究

为研究松软土壤下BH-1型六轮月球探测车原理样机的运动性能和越障性能,对原理样机的运动学和动力学进行了理论分析.通过推导BH-1型原理样机车体和车轮的运动学约束关系,研究车轮的前向滑移、转向角滑移及侧向滑移对样机运动学的影响;鉴于月球表面松软的砂质土壤条件,对样机的车轮力学情况进行分析,进而建立基于凯恩方程的机器人动力学模型;利用ODE(open dynamics engine)三维动力学仿真软件对样机的越障过程进行仿真演示.仿真结果证明,BH-1具有优秀的运动性能和越障性能.     

气动三自由度并联机器人设计与仿真分析

为了设计一种具有良好运动学性能的并联机器人,以基于气浮无摩擦缸驱动的3-UPU并联机器人为研究对象,对其进行运动学建模以及工作空间、动力学仿真分析。通过三维建模软件设计3-UPU并联机器人物理模型;根据机器人几何关系推导其运动学方程并基于数值解法得到该机器人的工作空间;采用遍历法求解机器人各支链旋转角度范围,从而得到该机器人在其工作空间的最大输出力分布情况。仿真结果表明,该机器人具有良好的运动学性能。     

井工开采对边坡稳定性影响的有限元分析

边坡下方井工开采是一个露天煤矿普遍存在的问题。本文采用有限元方法针对某一具体实例进行了数值模拟。模拟考虑了岩体力学特性及岩体结构特征,并模拟了井采过程。通过井采前后边坡岩体应力分析、位移分析,对边坡下方井工开采对边坡稳定性影响获得了一些认识。     

Pore pressure fluctuations of overlying aquifer during residual coal mining and water-soil stress coupling analysis

Three test models and a simulation model were constructed based on the prevailing conditions of the Taiping coalmine in order to analyze pore pressure fluctuations of an overlying aquifer during residual coal mining. As well, the relation between pore pressure and soil stress was evaluated. The model tests show the vibrations of pore pressure and soil stress as a result of mining activities. The simulation model tells of the response characteristics of pore pressure after mining and its distribution in the sand aquifer. The comparative analysis reveals that pore pressure and soil stress vibration are activated by unexpected events occurring in mines, such as collapsing roofs. An increased pore pressure zone always lies above the wall in front or behind the working face of a mine. Both pore pressure and vertical stress result in increasing and decreasing processes during movements of the working face of a mine. The vibration of pore pressure always precedes soil stress in the same area and ends with a sharp decline. Changes in pore pressure of sand aquifer are limited to the area of stress changes. Obvious changes are largely located in a very small frame over the mining face.     

FEM modeling for 3D dynamic analysis of deep-ocean mining pipeline and its experimental verification

3D dynamic analysis models of 1000 m deep-ocean mining pipeline, including steel lift pipe, pump, buffer and flexible hose, were established by finite element method (FEM). The coupling effect of steel lift pipe and flexible hose, and main external loads of pipeline were considered in the models, such as gravity, buoyancy, hydrodynamic forces, internal and external fluid pressures, concentrated suspension buoyancy on the flexible hose, torsional moment and axial force induced by pump working. Some relevant FEM models and solution techniques were developed, according to various 3D transient behaviors of integrated deep-ocean mining pipeline, including towing motions of track-keeping operation and launch process of pipeline. Meanwhile, an experimental verification system in towing water tank that had similar characteristics of designed mining pipeline was developed to verify the accuracy of the FEM models and dynamic simulation. The experiment results show that the experimental records and simulation results of stress of pipe are coincided. Based on the further simulations of 1 000 m deep-ocean mining pipeline, the simulation results show that, to form configuration of a saddle shape, the total concentrated suspension buoyancy of flexible hose should be 95%?105% of the gravity of flexible hose in water, the first suspension point occupies 1/3 of the total buoyancy, and the second suspension point occupies 2/3 of the total buoyancy. When towing velocity of mining system is less than 0.5 m/s, the towing track of buffer is coincided with the setting route of ship on the whole and the configuration of flexible hose is also kept well.     

Experimental research of overburden movement and subsurface water seeping in shallow seam mining

Shallow seam coal field has the largest coal reserve in China. Mining in shallow depth causes serious problems, and sub- surface dewatering is a major issue. In this paper, the physical simulating models were prepared to study overburden movement and aquiclude stability in the shallow seam mining of Yushuwan Coalfield, China. According to the characteristic of clay aquiclude and bedrock in the overburden, the proper simulation materials for simulating the plastic clay aquiclude layers and brittle bedrock layers were determined by the stress-strain tests and hydrophilic tests. The physical simulating models of solid medium and two phases of solid-liquid medium were carried out to simulate the failure and caving process of the roof and overburden, as well as the subsurface water seeping. Based on the simulation, it was found that the movement of clay aquiclude follows the movement of the underlying bedrock layers. The stability of aquiclude is mainly affected by cracks in fracture zone. The tests also showed that the best way to control the stability of aquiclude is to reduce the subsiding gradient, and there is a possibility of ground water conservation under longwall mining in Yushuwan Mine. This research provides a foundation for further study on mining dewatering and water conserva- tion.     

Numerical simulation of protection range in exploiting the upper protective layer with a bow pseudo-incline technique

The developing processes of stress and deformation fields of a protected layer after mining an upper-protective layer with a bow pseudo-incline technique were simulated to locate the protection region. The pressure relief of the protected layer was analyzed after mining the upper-protective layer. The pressure relief angle along the strike and incline were located according to the rules of protection of the deformation and stress pressure-relief of the protective layer after mining. This results show that the up-per-protective layer with the bow pseudo-incline technique have an upper and downside pressure relief angle of 85 and 68 degrees respectively; the distribution of strike pressure relief angles along the pseudo-incline working face is uneven and their values range from 38.3 to 51 degrees. The pressure relief angle of the inclined middle location was the largest. The distribution of the protection region of the upper-protective layer with the bow pseudo-incline technique located by practical tests and numerical simulation is essentially consistent, compared with the results obtained by these methods.     

基于ADAMS的ROV采矿车近海底着地虚拟仿真

为了研究ROV采矿车在深海钴结壳开采中的作业性能,论证ROV用于深海采矿的可行性,为ROV深海采矿车作业进行预报,借助了多体动力学仿真软件ADAMS,运用了虚拟样机技术对ROV采矿车的近海底着地过程进行动力学仿真．首先应用SolidWorks软件建立起ROV采矿车的三维实体模型,并导入了机械系统动力学分析软件ADAMS中建立虚拟样机,在深海环境下对该虚拟样机近海底着地进行了多体动力学仿真,其结果表明ROV采矿车在近海底着地时切削头与地面存在着碰撞,该碰撞是强烈的．对此提出了一种改进策略,让采矿车在推进器控制下实现0速度着地,切削头与地面的碰撞大大减轻,该控制方法效果良好．     

Modeling and simulation of crushing process of spiral mining head

1 INTRODUCTIONThe research of mining deep seabed cobalt-richcrust is a hotspot of international oceanology[1].Based on the mining manganese nodule ,lots of re-searches on mining cobalt crust have been madedeeply and many kinds of methods ,such as thei m-proved CLB, mining vehicle +lifting system +surface supporting ship have been put forward.Mining vehicle consists of collecting machine ,tracked treading machine and spiral mininghead[2 ,3].The first step of mining cobalt crust is tocrush…     

通信网告警相关性分析中有效的关联规则挖掘算法

关联规则挖掘算法是通信网告警相关性分析中的重要方法。在处理数量庞大的告警数据库时,算法的效率显得至关重要,而经典的FP-growth算法会产生大量的条件模式树,使得在通信网环境下挖掘关联规则的难度非常大。针对上述问题,提出了一种基于分层频繁模式树的LFPTDP算法,采用分层模式树的方法产生频繁项集,从而避免了产生大量的条件模式树,并用动态剪枝的方法删除大量的非频繁项。算法分析及仿真表明,LFPTDP算法具有较好的时间和空间效率,是一种适合于通信网告警相关性分析的关联规则挖掘算法。     

Monte Carlo Analytic Hierarchy Process (MAHP) approach to selection of optimum mining method

One of the most critical and complicated steps in mine design is a selection of suitable mining method based upon geological, geotechnical, geographical, safety and economical parameters. The aim of this study is developing a Monte Carlo simulation to selection the optimum mining method by using effective and major criteria and at the same time, taking subjective judgments of decision makers into consideration. Proposed approach is based on the combination of Monte Carlo simulation with conventional Analytic Hierarchy Process (AHP). Monte Carlo simulation is used to determine the confidence level of each alternative’s score, is calculated by AHP, with the respect to the variance of decision makers’ opinion. The proposed method is applied for Jajarm Bauxite Mine in Iran and eventually the most appropriate mining methods for this mine are ranked.     

短壁机械化开采方法与煤柱稳定性研究

开发适合我国现代化矿区“三下”开采及边角煤开采的短壁机械化开采成套技术具有十分重要的现实意义．根据国产短壁机械化开采设备情况，结舍“三下”开采需留设煤柱保护地表的实际，提出了3种短壁机械化开采的巷道布置方式，研究了短壁机械化开采工艺及设备配套．采用岩石破裂过程分析软件RFPA2D系统，对短壁机械化开采的煤柱稳定性进行数值计算与分析．研究结果应用于五阳煤矿村庄下采煤实践，实现了安全、高效开采，并有效控制了地表沉陷．