Calculation method of load distribution on pipe threaded connections under tension load

This paper presents a new calculation method that can calculate the load distribution on pipe threaded connections under tension load. On the basis of elastic mechanics, the new method was developed by analyzing each thread tooth, and a new deformation and covariant equation by making a mechanics analysis on each thread tooth was obtained. Compared with the traditional method proposed by the previous references, the new deformation and covariant equation could be used to describe the relation between the previous and the next thread tooth. By applying the new method on the sample of P-110S pipe threaded connection, the obtained results show that the load on thread tooth mainly concentrates on the four or five threads engaged and the middle teeth were not utilized well to bear the loads. The model offers a new way to calculate the loads carried on the thread teeth under tension load.     

Model of threaded joints with a uniform load distribution over the turns

The uniform distribution of contact forces over the turns of a thread with technological gaps is considered. The goal is to develop technologies that ensure rational load distribution over the turns of a thread.     

温度载荷对特殊螺纹油管接头密封性能的影响

为分析高温、高压及轴向力复合作用对特殊螺纹油管接头密封性能的影响,在考虑螺纹升角的情况下采用SolidWorks建立接头三维有限元模型,在有效模拟接头上扣的基础上,分析轴向力与内压共同作用下不同温度对接头密封面和台肩完整性的影响.结果表明:复合载荷作用下,随着温度升高,密封面和台肩Mises应力增大,密封面接触压力减小,台肩接触压力持续增大.复合载荷作用下接头密封面接触良好且未发生塑性变形,同时台肩对接头起到良好的辅助密封作用.     

弹塑性变形对螺栓应力和轴力分布的影响

为了解决液压机用锯齿形螺纹在啮合螺纹段第一扣牙根处的疲劳断裂问题,采用非线性有限元数值模拟方法,以ANSYS软件为工具,考虑螺栓和螺母材料的弹塑性,研究了不同轴力作用下啮合螺纹段的应力和变形规律.给出不同轴力下螺栓啮合螺纹段中轴力和牙根峰值等效应力沿螺母高度的非线性分布规律,得出螺母螺纹约70%塑性变形可使螺栓牙根峰值等效应力和牙间轴力趋于均匀分布的结论,为大型螺栓连接结构的弹塑性设计提供了有益指导.     

Optimal load distribution between units in a power plant

This paper presents a strategy for load distribution between the generating units in hydro power plants. The objective is to reach the maximum energy conversion efficiency for a given dispatched power. The developed tool employs a heuristic-based combinatorial optimization technique in conjunction with a set of system variables measurement allowing real-time load sharing. The developed equipment is used to give online energy conversion efficiency from each unit of the power plant. No specific previous information about the efficiency of system components is required. Simulation results of the proposed optimization technique when applied to typical hydro power plant data are presented.     

Analysis of sprocket load distribution

A study was made to determine the load distribution for an elastic roller chain on an elastic sprocket. The equations developed for the distribution include, as a subset, those for a rigid roller chain on a stationary rigid sprocket. The effect of friction and sprocket rotation on load distribution is discussed. Results are presented for a 20-tooth sprocket with a 180° angle of roller chain wrap, for various tight-to-slack side tension ratios of both driver and driven sprockets, with various spring constant ratios.     

基于ANSYS的烤箱管接头的风载分析

烤箱管接头是电容老化设备的重要组成部分,为电容老化提供了必要的温度场,它在高温下的应力、应变参数直接影响到电容老化的效果.采用ANSYS软件对烤箱管接头进行三维实体建模和静态分析,得到了此结构在风载荷和重力作用下的应力和应变结果.分析了风载荷和重力作用下的应力、应变对此烤箱管接头的影响,结果表明烤箱管接头出现最大应力和...     

Experimental and numerical study of the load distribution in a ball-screw system

In this work, load distribution on ball-screw systems (BSS) is determined by experimental techniques. Two optical techniques are used: photoelasticity for stress-field measurement and the mark-tracking method for displacement-field determination. In parallel to the experimental study, finite element method (FEM) and analytical solutions are used to calculate the loads applied on each ball of the BSS. Experimental results are used to validate the choice of boundary conditions and contact conditions between ball-screw and ball-nut in the FEM solution. The validation criterion is the correspondence between numerical and experimental fringes representing the differences of principal stresses. In addition to the study of load distribution, this paper presents the influence of the angle of contact direction on the stress distribution in BSS.     

浅谈传感器桥路网络的对称性

本文对传感器桥路网络不对称布局引起多只传感器并联后零点产生异常,对计量精度的影响进行全面科学的分析,使大家了解了某些电子汽车衡产生偏载误差的原因.     

Strength of threaded joints

Fatigue tests of threaded joints are required to establish their fatigue strength. The manufacture of bolts, screws, pins, and nuts with MJ metric threads is expedient.     

弹性元件对受轴向工作载荷螺纹联接强度的影响

弹性元件作为一种常用的机械元件,经常应用于螺纹联接中。为了深入分析弹性元件对螺纹联接强度的影响,对不同联接方式下的螺栓联接进行了刚度分析和受力分析,从理论上提出弹性元件有增大螺栓相对刚度、增大螺栓受力的作用,由此得出弹性元件削弱螺纹联接强度的观点。同时,应用ANSYS仿真软件对不同联接方式下的螺栓联接进行有限元仿真分析,以螺栓的受力、变形的差异说明理论分析的正确性。将这一正确结果应用在实际工程中,有助于提高螺纹联接的强度。     

Force distribution for a flat belt drive with a concentrated contact load

An equation based on the classical Euler formula is derived to investigate the normal and tangential belt force distribution of a flat belt drive when a concentrated contact load is applied on the pulley. This loading condition occurs in an abrasive belt grinding. The belt force equation presented in this paper has a constant coefficient of friction. Analytical results show good agreement with the experimental results and the authors' previous work, which is based on a surface model of the belt friction face with a varying coefficient of friction. The equation developed from the Euler formula is suggested for practical design due to its sufficient accuracy and simplicity.     

一种连接结构对螺纹连接的影响分析

通过对项目施工中遇到的一种地脚螺栓连接结构的分析，发现不恰当的连接结构设计对螺纹连接的不利影响，对工程有一定借鉴意义。     

配电线路导体对接9要点

供配电线路运行中电线、母排等导体因输电距离、线路变向转角等原因,需要进行不同导体间的对接,当有中间接头的输电线路输送的电流流量在其安全载流量允许范围时,因对接不当会引起导体过热、甚至引发生产事故.通过生产实例说明了按照环境条件严格选线并且在安全载流量条件下对接导体过热故障现象,以及由此引发的事故现象.分析了故障和事故产生的原因.指出了线路中导体合理对接的9个要点.     

用KHβ新算法研究齿轮轮齿载荷分布

提出齿轮轮齿齿向载荷分布系数KHβ新的计算方法,并用此方法对影响KHβ的各种因素进行电算分析.新算法舍弃了齿轮强度国家标准中,轮齿载荷分布沿齿向成线性的假设条件,依据轮齿的载荷-变形协调关系,把影响载荷分布系数KHβ的各类误差归结为影响轮齿齿向的初始载荷分布,最终确定在动态条件下轮齿啮合线上的稳定载荷分布,再由KHβ的定义算得轮齿的载荷分布系数KHβ.利用新算法得到的轮齿齿宽、齿轮轴长、齿轮在轴上几何位置和齿轮精度等因素对KHβ影响的关系曲线,可供齿轮强度设计人员参考.     

自动负荷分配器在发电机组并联运行中的应用

文章介绍了自动负荷分配器的技术性能、各种功能及在发电机组并联运行中作用、调试方法及其必要性.     

Screw tightening in dynamically loaded threaded joints

The need for an increased tightening torque in threaded joints dynamically loaded by a rupture force is theoretically established.     

Increasing the strength of threaded joints

The maximum equivalent stress in a threaded joint may be reduced by 50% by adjusting the pitch within the joint.     

Extending the life of threaded joints

The influence of design and technological factors on the life of pins attaching a ball bearing to the housing of a truck’s front driven axle is experimentally studied.     

带式输送机多卷筒驱动最佳负荷分配

从理想的负荷分配出发,给出了合理的多卷筒负荷分配值,使胶带的最大张紧力接近最小,为带式输送机设计和改造提供了理论根据。