共查询到19条相似文献,搜索用时 109 毫秒
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本文介绍由0Cr17Ni4Cu4Nb材料制造的超高压缸体自增强处理试验结果,给出了四个缸体外壁面的p-εto曲线和其残余应力,与十二边形准则的计算结果相比较十分吻合。最后本文讨论了以压力控制超应变度的合理观点。 相似文献
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超高压容器损伤自增强的应力分析 总被引:5,自引:0,他引:5
从损伤力学的理论观点,区别于弹塑性力学的角度,研究了超高压容器的损伤自增强,进行了超高压厚壁筒损伤自增强的应力分析,通过残余应力的计算,充分说明了利用超高压厚壁容器内壁损伤可以产生自增强的效果。这一结论为超高压厚壁容器自增强理论研究,提供了新的探讨方向。 相似文献
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某设备的缩套式超高压缸体存在内壁始终为应力最大位置,且缸体应力分布相当不均匀的问题。为满足缸体最大等效应力小于缸体材料的屈服极限,以内外缸体内壁剪应力相等为约束条件,结合过盈配合及设计要求,利用响应面法对缩套式超高压缸体进行优化设计。结果表明,缸体的过盈量从优化前的0.30 mm减小到优化后的0.2662 mm,降低了内外缸安装套合时的工作难度;内缸内壁到外缸内壁的等效应力的变化率从优化前的0.787 MPa/mm降为0.0568 MPa/mm,缸体的应力分布不均匀性较优化前有了较大的改观。 相似文献
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该文基于超高压气体设备操作的安全性,结合现代科技,设计出一种基于LabVIEW的超高压气体远程测控系统。该系统克服传统的超高压气体设备控制方法的安全性难以保证、功能实现单一、数据处理简单、远程控制距离有限等缺点,能够实时监测、控制高压气体。有效地解决了现场操作人员的人身安全问题,具有操作简单、实时性好、数据管理方便等特点。 相似文献
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对某公司存放15年的超高压自增强反应管备管的残余应力进行了理论计算和试验测试,采用镗削法测定了自增强超高压反应管的残余应力值,根据M ises变形能量理论推导出残余应力的计算公式,计算出自增强处理后的超高压反应管的残余应力。 相似文献
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LabVIEW中的动态连接库调用 总被引:1,自引:0,他引:1
介绍了LabVIEW调用Win32动态连接库的方法,并通过实例,分析了LabVIEW与外部代码进行连接的机制,增强了LabVIEW的系统开发能力. 相似文献
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Thermal autofrettage is a potential process to generate beneficial compressive residual stresses at and around the inner wall of a thickwalled cylinder for increasing its pressure carrying capacity. Due to its simplicity and inexpensive arrangement, it can compete with the conventional hydraulic autofrettage process. In this work, a comparative study of the thermal autofrettage and the hydraulic autofrettage is carried out. As the thermal autofrettage does not require hydraulic power pack, the process is more economical than the hydraulic autofrettage. The thermal autofrettage process is also studied for the thick-walled cylindrical vessels subjected to high thermal gradient with or without pressure and is compared with the hydraulic autofrettage. Comparison shows that for cylinders subjected to high thermal gradient without pressure, the thermal autofrettage is superior to the hydraulic autofrettage. 相似文献
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由于Bauschinger效应的影响,自紧厚壁管反向屈服现象普遍存在,使得内壁残余应力减少,厚壁管承载能力下降,因此,通过复合机械自紧技术,可消除Bauschinger效应,提高自紧厚壁管的弹性强度。本文在理论上和工艺上对复合自紧技术进行了研究,结果表明可大幅提高自紧 厚壁管的强度,这对自增强压力容器和管道设计具有指导意义。 相似文献
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基于三剪统一强度准则,考虑材料应变强化效应、包辛格效应、拉压异性及中间主应力的影响,采用双线性强化材料模型对厚壁圆筒进行自增强分析,得到了厚壁圆筒加载应力、残余应力和工作应力的解析解,提出了最佳自增强压力的计算方法,探讨了拉压比、强度准则变化参数的影响,比较了自增强处理和非自增强处理及双线性强化模型和理想弹塑性模型厚壁圆筒的应力分布差异。研究结果表明:厚壁圆筒的最佳自增强压力随半径比和强度准则参数的增大而增大;工作时的最大等效应力随半径比和强度理论参数的增大而减小,随拉压比的增大而增大;自增强等效应力的最大值在弹塑性分界面处,且应力沿壁厚的分布较均匀;与理想弹塑性模型相比,双线性强化模型所对应的弹塑性分界面半径和残余应力较小,且随着自增强压力的增大,两种模型的差值越来越大;等效应力随半径比的变化规律可为厚壁圆筒选择合理的壁厚提供一定的参考;自增强技术可改善厚壁圆筒工作时的实际应力分布,提高其极限承载能力。 相似文献
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Analysis on autofrettage of cylinders 总被引:1,自引:1,他引:0
Autofrettage is an effective technique to improve load-bearing capacity and safety for pressure vessels.For autofrettaged cylinder,the depth of plastic zone,or overstrain is a key factor which affects load-bearing capacity and safety.The previous research on overstrain was not done in terms of the point of view of raising load-bearing capacity as far as possible and simultaneously avoiding compressive yield for cylinders experiencing autofrettage handling,and there were no analytic solutions of autofrettage in the above view point presented,the 3rd and 4th strength theories were not applied synthetically in the research to compare the results from these two theories.In this paper,with the aid of the analytic method,based on summing up the authors’ previous research,results from autofrettage of a cylinder based on the 3rd and 4th strength theories are studied and compared,and the laws contained in the results are looked into.Then,the essential cause and reason for the obtained laws are analyzed and the inherent and meaning relations between various parameters in autofrettage theory are revealed.It is shown that the maximum radius ratio for equivalent residual stress at inside surface never exceeds the yield strength even for a cylinder experiencing wholly yielded autofrettage,or the critical radius ratio is kc=2.218 457 489 916 7…,irrespective of the 3rd or 4th strength theories.The equation relating the depth of plastic zone with the thickness of a cylinder is identical for the 3rd and 4th strength theories.In form,the optimum load-bearing capacity of an autofrettaged cylinder is two times the initial yield pressure of the unautofrettaged cylinder irrespective of the 3rd or 4th strength theory.The revealed inherent relations between various parameters and varying laws of the parameters as well as the forms of the relations under the 3rd and 4th strength theories not only have theoretical meanings but also have prospects in engineering application. 相似文献
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自增强是通过提高压力容器的残余应力来增强他们的承载能力和疲劳寿命。自增强复合圆筒可以承受比一个具有相同尺寸的单层圆筒更高的压力。引入了应变硬化模型,对自增强复合圆筒的残余应力进行了分析,并对其分布进行了预测。研究表明:复合圆筒内壁的切向残余应力和应力幅随着超应变度的增大而增大。缩套是提高压缩残余应力的一个非常有效的方法。 相似文献
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Qiu-Ming Yang Young-Shin Lee Eun-Yup Lee Jae-Hoon Kim Ki-Up Cha Suk-Kyun Hong 《Journal of Mechanical Science and Technology》2009,23(11):2913-2920
A program for the residual stress analysis of an autofrettaged compound cylinder is designed using a Matlab graphical user
interface (GUI) and program design technique. The high-pressure vessels are autofrettaged in order to increase their operating
pressure and fatigue life. An autofrettage process causes plastic expansion of the inner section of the cylinder, adding residual
compressive stress to the bore after relaxation. Such a compound cylinder is produced via a shrink-fit procedure that incorporates
a monobloc tube that has previously undergone autofrettage. This paper presents a simple and visual tool to calculate the
residual stress and describe the distribution of residual stress for both the elastic-perfectly plastic model and the strain-hardening
model. 相似文献
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Common rail pipe in a clean diesel vehicle plays a key role in supplying fuel from a rail to an injector of each cylinder connecting engine under a repeated internal pressure. For satisfying EU emission standards, fuel injection pressure is increased to be over 200 MPa, and it causes stress concentration at the outer surface of neck part with discontinuity and complexity of shape of the pipe. For preventing folding defects and for improving a fatigue life, integrated design of a heading process and an autofrettage process are required because the methods for reducing the stress concentration by using changing design, material and adding heat treatments cause considerable effects on performance and price of the pipe. In this study, the heading process for checking folding defects of pipe head is performed by FEA, and an autofrettage process is designed for improving a fatigue life by considering the stress concentration at the complex and discontinuous shape. The optimal autofrettage pressure is required not only to relieve the stress concentration but also to be not beyond the allowable internal pressure for the process safety. The allowable internal pressure for the autofrettage process is determined by using theoretical analysis and FEA, and the stress distributions through the autofrettage process are obtained by using the commercial software, ANSYS-Workbench. On the basis of the FEA results, the autofrettage pressure is optimized, and SEM (scanning electron microscope) and fatigue tests were performed for prototypes to validate analysis of the integrated process design (Heading process and the autofrettage process). 相似文献