光纡压力传感器探头的设计

介绍了一种光纤压力传感器探头的设计和计算。利用平膜片实现压力与位移的转换,其位移由光纤传感器检测出来。探头中两光纤呈θ角度放置,能使系统的灵敏度达到41.6mV/MPa。传感器探头的最大承压为3mPa。     

CO2气体保护焊控制系统及其实现

为了控制CO2气体保护焊过程中焊接电弧的稳定,提出了焊接电流和平均燃弧电压双闭环实时控制模式并进行了试验研究.在燃弧峰值和燃弧基值分离控制的基础上,研究了两者对电弧稳定性的影响规律,首次提出燃弧占空比的概念,并指出燃弧占空比是CO2气体保护焊过程中电弧稳定性的决定因素.该控制模式通过实时改变峰值电流持续时间调整燃弧占空比,实现了电弧电压的自动调整,保证了焊接过程的稳定性.     

One-knob self-optimizing fuzzy cotrol of CO2 arc welding process

A new one-knob self-optimizing fuzzy control system of CO2 arc welding is established based on the syntheitic performance evaluation of droplet transfer process.It includes two kinds of self-optimizing fuzzy controllers;the arc voltage controller and the current waveform controller,The fuzzy control principle and the key points of the control patterns are presented.Through on -line detecting,computing of characteristic parameters and one-knob self-optimizing adjusting.the characteristic parameters and welding variables can be adjusted to suitable ranges under the control of the arc voltage controller,Meanwhile the current waveform controller is active in the rear-time stage of the short-circuiting and the instant of re-triggering arc.The experiment results show that the control and its algorithm can improve the synthetic performance of arc welding process apparently.     

Finite element synthesized analysis of the forming process of spiral welded pipe

Numerical simulation concerning the forming and welding process of spiral welded pipe was conducted, which included three steps ： the first step was the stress analysis when the spiral was formed, and then the stress was regarded as initial condition of melding during the temperature field analysis in the process of welding, the last step was the thermal stress analysis of the weld seam after the welding was over. Moreover, when the steel strip was pushed, the stress was also calculated by non-linearity contact technology using Abaqus Software. By finite element modeling and calculating of the forming and welding process of the spiral welded pipe, the key points of the multi-fields synthetic simulating were studied and discussed.     

CO2弧焊熔滴过渡过程的特征及其定量评价

研究了ＣＯ２焊接熔滴短路过渡特征参数及其统计规律，结果表明各特征参数对ＣＯ２焊接短路过渡过程变化的敏感程度不一致，某些特征参数的敏感性比短路过渡频率更强烈。为综合考虑这些参数的影响，以特征参数综合值来描述和实时评判ＣＯ２焊接短路过渡过程，得到一个能全面定量描述和评判ＣＯ２焊接过程的综合评价函数。试验和评判表明，该评价函数能够对ＣＯ２焊接短路过渡过程的不同规范状态给予综合评价。     

CO_2弧焊熔滴过渡过程焊接电弧的并联式波形控制

提出并实现了一种新型的并联式电弧波形控制法 ,设计了相应的IGBT波形控制器 ,该法可用于CO2 弧焊熔滴过渡过程电弧的波形控制。对焊接电弧参数实时采样以及工艺试验表明 ,所研制的波控器对减少金属飞溅和改善焊缝成型均有明显效果     

CO2弧焊电流波形的多参数自寻优智能控制

研究并提出了一种CO2气体保护焊电流波形的多参数自寻优智能控制法,电流波形的模糊寻优计及弧焊过程特征参数的综合影响,并在表征短路过渡综合性能的特征综合值作为弧焊过程定量评价和目标实时寻优的函数。在波控参数基值的基础上,基于综合性能寻优过程采用三级模糊调节算法,对电流波形参数分步调节寻优。该法实际上将双输入三输出式的波控参数模糊控制系统化为多路,开关性的双输入单输出式的模糊控制,通过短路及燃弧初始阶段的电流波形控制参数的模糊自寻优,逐步使波控参数和焊接规范参数达到和谐匹配,以实现焊接过程熔滴的稳定可控过渡,改善焊接过程的综合性能。     

基于ANSYS的TIG焊接电弧数值模拟研究

焊接电弧的数值模拟是一个复杂而重要的工程.通过理论假设,对TIG焊接电弧的数学模型进行了简化,成功地建立了实用的焊接电孤瞬态温度分布数学模型.采用有限元分析软件ANSYS,探索了电孤模拟分析中热、电磁、流场和温度场的耦合理论;采用过渡网格划分的非均匀网格划分方式,在保证计算精度的基础上,有效地缩短了模拟计算的时间,电弧温度场、电磁场的模拟计算结果与理论值和实验值基本吻合.     

重力分离自蔓延法制备a-Al_2O_3基复合陶瓷内衬管

采用重力分离自蔓延高温合成(Self-propagating High-temperature Synthesis)制备了a-Al2O3基复合陶瓷内衬复合管,研究了添加CuO、纳米SiC对陶瓷层制备及其组织的影响。XRD分析表明,陶瓷层的主要成分为a-Al2O3,还有少量铁铝尖晶石FeAl2O4和硅线石Al2SiO5及SiC存在,CuO、SiC有利于改善组织结构,促进晶粒细化。CuO作为助燃剂,可提高燃烧速度和燃烧温度并减少陶瓷中FeAl2O4的含量。纳米SiC的引人有效地抑制了基质晶粒生长和减轻了晶粒的异常长大,使得陶瓷层的硬度和致密性提高。