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An analysis of Liver and Kidney pathogenesis and treatment based on the theory of interpromotion and restraint of the five elements
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作者 Rui Xu 《Medical Theory and Hypothesis》 2022年第3期27-28,共2页
The interpromotion and restraint of the five elements is the self-regulation mechanism of the five elements system under normal conditions.For the human viscera,by comparing the images,deducing and classifying the att... The interpromotion and restraint of the five elements is the self-regulation mechanism of the five elements system under normal conditions.For the human viscera,by comparing the images,deducing and classifying the attributes of things,the human viscera are connected with the five elements,and it is concluded that the Liver belongs to Wood and the Kidney belongs to Water.According to the law of mutual generation and restriction between the five elements,the pathogenic causes,pathogenesis and relationship with other viscera of the Liver and Kidney can be known,so as to establish corresponding treatment methods,such as"Nourishing Water and protecting Wood"(providing Kidney for the growth of Liver method),"Golden Water symbiosis"(generation between the Lung and Kidney),"Cultivating soil and generating gold"(warming the Kidney and benefited Spleen method),Supporting lung to suppress Liver,purging heart Fire to nourish renal Water method,etc.It is of referential significance for the treatment of Liver and Kidney diseases in the diagnosis and treatment of traditional Chinese medicine. 展开更多
关键词 five elements interpromote and restrain similarities and differences between Chinese and Western Medicine PATHOGENESIS Liver and Kidney
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Element-free Galerkin method for free vibration of rectangular plates with interior elastic point supports and elastically restrained edges 被引量:1
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作者 王砚 王忠民 阮苗 《Journal of Shanghai University(English Edition)》 CAS 2010年第3期187-195,共9页
The element-free Galerkin method is proposed to solve free vibration of rectangular plates with finite interior elastic point supports and elastically restrained edges.Based on the extended Hamilton's principle for t... The element-free Galerkin method is proposed to solve free vibration of rectangular plates with finite interior elastic point supports and elastically restrained edges.Based on the extended Hamilton's principle for the elastic dynamics system,the dimensionless equations of motion of rectangular plates with finite interior elastic point supports and the edge elastically restrained are established using the element-free Galerkin method.Through numerical calculation,curves of the natural frequency of thin plates with three edges simply supported and one edge elastically restrained,and three edges clamped and the other edge elastically restrained versus the spring constant,locations of elastic point support and the elastic stiffness of edge elastically restrained are obtained.Effects of elastic point supports and edge elastically restrained on the free vibration characteristics of the thin plates are analyzed. 展开更多
关键词 element free method rectangular thin plates interior elastic point supports elastically restrained edges free vibration
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Hydration Process and Crack Tendency of Concrete Based on Resistivity and Restrained Shrinkage Crack 被引量:1
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作者 MUAZU Bawa Samaila 魏小胜 WANG Lei 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2016年第5期1026-1030,共5页
Hydration process, crack potential and setting time of concrete grade C30, C40 and C50 were monitored by using a non-contact electrical resistivity apparatus, a novel plastic ring mould and penetration resistance meth... Hydration process, crack potential and setting time of concrete grade C30, C40 and C50 were monitored by using a non-contact electrical resistivity apparatus, a novel plastic ring mould and penetration resistance methods, respectively. The results show the highest resistivity of C30 at the early stage until a point when C50 accelerated and overtook the others. It has been experimentally confirmed that the crossing point of C30 and C50 corresponds to the final setting time of C50. From resistivity derivative curve, four different stages were observed upon which the hydration process is classified; these are dissolution, induction, acceleration and deceleration periods. Consequently, restrained shrinkage crack and setting time results demonstrated that C50 set and cracked the earliest. The cracking time of all the samples occurred within a reasonable experimental period thus the novel plastic ring is a convenient method for predicting concrete's crack potential. The highest inflection time(t_i) obtained from resistivity curve and the final setting time(t_f) were used with crack time(t_c) in coming up with mathematical models for the prediction of concrete's cracking age for the range of concrete grade considered. Finally, an ANSYS numerical simulation supports the experimental findings in terms of the earliest crack age of C50 and the crack location. 展开更多
关键词 concrete electrical resistivity restrained shrinkage crack setting time finite element simulation
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Non Degeneration of Fibonacci Series, Pascal’s Elements and Hex Series
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作者 Balasubramani Prema Rangasamy 《Advances in Pure Mathematics》 2020年第7期393-404,共12页
Generally Fibonacci series and Lucas series are the same, they converge to golden ratio. After I read Fibonacci series, I thought, is there or are there any series which converges to golden ratio. Because of that I ex... Generally Fibonacci series and Lucas series are the same, they converge to golden ratio. After I read Fibonacci series, I thought, is there or are there any series which converges to golden ratio. Because of that I explored the inter relations of Fibonacci series when I was intent on Fibonacci series in my difference parallelogram. In which, I found there is no degeneration on Fibonacci series. In my thought, Pascal triangle seemed like a lower triangular matrix, so I tried to find the inverse for that. In inverse form, there is no change against original form of Pascal elements matrix. One day I played with ring magnets, which forms hexagonal shapes. Number of rings which forms Hexagonal shape gives Hex series. In this paper, I give the general formula for generating various types of Fibonacci series and its non-degeneration, how Pascal elements maintain its identities and which shapes formed by hex numbers by difference and matrices. 展开更多
关键词 Fibonacci Series Lucas Series Golden Ratio Various Type of Fibonacci Series generated by Matrices Matrix Operations on Pascal’s elements and Hex Numbers
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模块化防屈曲钢板墙抗震性能 被引量:1
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作者 金华建 孙飞飞 +4 位作者 李国强 李可军 常明媛 陈明玲 陈韬 《东南大学学报(自然科学版)》 EI CAS CSCD 北大核心 2024年第1期25-35,共11页
考虑经济性和便利性,提出了模块化防屈曲钢板墙及其常用模数,然后基于已有的防屈曲钢板墙的简化计算模型,推导了在不同墙数量情况下,模块化防屈曲钢板墙充分发挥抗震性能时,周边梁的承载力和刚度需求,并提出了周边梁的设计方法.进而,对... 考虑经济性和便利性,提出了模块化防屈曲钢板墙及其常用模数,然后基于已有的防屈曲钢板墙的简化计算模型,推导了在不同墙数量情况下,模块化防屈曲钢板墙充分发挥抗震性能时,周边梁的承载力和刚度需求,并提出了周边梁的设计方法.进而,对模块化防屈曲钢板墙和整体墙进行了对比验证试验及其有限元模拟分析.研究结果表明:模块化防屈曲钢板墙能够达到与整体钢板墙相同的抗震性能,且周边梁未发生明显转动和破坏,说明所提出的周边梁设计方法是合理的;在层间位移角为1/50时,防屈曲钢板墙上下周边梁均未进入塑性,且承载力和初始刚度等的有限元值与试验值误差小于6%,从而进一步验证了其抗震性能. 展开更多
关键词 模块化防屈曲钢板墙 周边梁需求 设计方法 试验验证 有限元分析
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火灾下LYP160屈曲约束支撑抗震性能研究
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作者 何文福 李志威 +3 位作者 胡宝琳 胡吴彪 丁振坤 田华 《上海大学学报(自然科学版)》 CAS CSCD 北大核心 2024年第2期318-331,共14页
为研究屈曲约束支撑(buckling-restrained brace,BRB)及其体系在高温工况的抗震性能,对BRB芯材低屈服点LYP160钢材分别进行了常温和高温材料力学性能试验.通过与试验结果比较,建立了BRB热-力耦合精细化有限元分析模型,验证了该模型的准... 为研究屈曲约束支撑(buckling-restrained brace,BRB)及其体系在高温工况的抗震性能,对BRB芯材低屈服点LYP160钢材分别进行了常温和高温材料力学性能试验.通过与试验结果比较,建立了BRB热-力耦合精细化有限元分析模型,验证了该模型的准确性;对火灾下LYP160屈曲约束支撑的温度场、滞回曲线、骨架曲线和耗能能力等性能进行了对比分析;对不同工况(3种火灾工况和常温工况)下8层配置屈曲约束支撑钢框架(BRB structure,BS)和原结构(original structure,OS)分别进行了弹塑性动力时程分析.研究结果表明:3种火灾工况下BS的平均层间位移角较于OS分别降低了30.4%、33.2%和42%;OS柱塑性铰损坏严重,且更多出现在柱上,BS整体损坏程度较OS轻,更为安全可靠. 展开更多
关键词 屈曲约束支撑 低屈服点钢 火灾 有限元 抗震性能
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LY160钢屈曲约束支撑框架抗震性能研究
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作者 何文福 杨作栋 +3 位作者 胡宝琳 胡吴彪 丁振坤 田华 《工程抗震与加固改造》 北大核心 2024年第2期33-43,共11页
屈曲约束支撑(BRB)因其性能优越已在工程中广泛应用,目前工程中使用的BRB芯材多为Q235B钢,为研究软钢BRB框架的受力性能,设计了一榀LY160钢BRB框架进行低周反复试验。试验结果表明:LY160钢BRB框架滞回曲线饱满,耗能系数高达1.54,等效黏... 屈曲约束支撑(BRB)因其性能优越已在工程中广泛应用,目前工程中使用的BRB芯材多为Q235B钢,为研究软钢BRB框架的受力性能,设计了一榀LY160钢BRB框架进行低周反复试验。试验结果表明:LY160钢BRB框架滞回曲线饱满,耗能系数高达1.54,等效黏滞阻尼达到了0.255。为了进一步研究LY160钢BRB框架结构体系抗震性能,分别运用ABAQUS与PERFORM-3D对框架试验进行模拟,并将两个模拟结果与试验结果进行对比,分析了两个软件模拟计算的优缺点,验证了数值模拟的准确性。在此基础上,采用PERFORM-3D建立6层BRB框架结构(BRBS)模型并与无控框架结构(UCS)模型以及普通支撑框架结构(NBS)模型进行对比,BRBS的层间位移角、层剪力最高可分别降低34.47%、31.29%,远超NBS的19.39%和17.31%,且BRBS的塑性耗能几乎全为BRB提供,很好地保护了主体结构,具有较为稳定、良好的抗震性能。 展开更多
关键词 屈曲约束支撑 低周反复加载试验 有限元分析 抗震性能 结构响应
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可修复钢制屈曲约束支撑力学性能试验与数值模拟研究
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作者 熊琛 吴迪晟 +2 位作者 管民生 刘尤森 杜宏彪 《工程力学》 EI CSCD 北大核心 2024年第6期145-153,共9页
提出了一种可修复钢制屈曲约束支撑(RBRB),该支撑可通过核心板的局部替换实现支撑修复。RBRB各部件采用螺栓连接,无须拆除屈曲约束盖板即可实现核心板修复替换,修复过程简单。设计了两种不同核心板宽度的RBRB试件,并开展低周往复加载试... 提出了一种可修复钢制屈曲约束支撑(RBRB),该支撑可通过核心板的局部替换实现支撑修复。RBRB各部件采用螺栓连接,无须拆除屈曲约束盖板即可实现核心板修复替换,修复过程简单。设计了两种不同核心板宽度的RBRB试件,并开展低周往复加载试验,讨论了其滞回性能、失效模式以及累计塑性变形能力。试验结果表明RBRB滞回曲线较为饱满,具有稳定的滞回性能与良好的累计塑性变形能力。RBRB试件在核心板修复后滞回性能与修复替换前保持一致,表明其可修复性较好。对试件开展了数值模拟研究,并与试验结果进行对比,结果显示数值模拟的破坏形式及滞回曲线与试验结果吻合良好。 展开更多
关键词 屈曲约束支撑 可修复 拟静力试验 滞回性能 有限元分析
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装配式开孔不锈钢防屈曲支撑抗震性能试验研究
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作者 陈磊 王东升 +1 位作者 孙治国 钱辉 《工程力学》 EI CSCD 北大核心 2024年第7期226-238,共13页
为提升沿海工程结构中耗能构件的耐久性能,提出了装配式不锈钢防屈曲支撑(BRBs),分别采用奥氏体S304和双相型S2205不锈钢作为内芯板。对内芯板和外约束板进行开孔设计,实现定点耗能的同时方便震后对BRBs的损伤情况进行观察。通过拟静力... 为提升沿海工程结构中耗能构件的耐久性能,提出了装配式不锈钢防屈曲支撑(BRBs),分别采用奥氏体S304和双相型S2205不锈钢作为内芯板。对内芯板和外约束板进行开孔设计,实现定点耗能的同时方便震后对BRBs的损伤情况进行观察。通过拟静力试验分析了不同材质BRBs的滞回特性及抗震性能,并采用ABAQUS对试验进行了模拟。结果表明:设计的装配式开孔一字形BRBs,结构形式简单,整体稳定性好。不同材质BRBs的屈服后硬化程度差异较大,建议对奥氏体S304不锈钢BRBs刚度因子取0.1,双相型S2205不锈钢BRBs刚度因子取0.02。两种不锈钢BRBs的等效粘滞阻尼比在L/100位移幅值下为0.4左右,均表现出了良好的耗能能力。在相同加载位移幅值下,奥氏体S304和双相型S2205不锈钢BRBs,与屈服强度分别相近的Q235和Q550普通钢BRBs相比,在低周疲劳寿命、塑性变形能力和总耗能等方面都分别远高于后者,具有更优的抗震性能。拟合得到的内芯板循环本构参数能够描述BRBs的滞回特性,采用的建模方法能够兼顾计算精度和计算效率。 展开更多
关键词 防屈曲支撑 不锈钢 拟静力试验 抗震性能 有限元分析
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可更换屈曲约束支撑的有限元分析
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作者 方东健 窦立军 《工程抗震与加固改造》 北大核心 2024年第1期35-41,62,共8页
针对传统屈曲约束支撑结构在震后修复困难、需要整体更换等问题,本文根据“定点屈服”原理,提出一种新型可更换屈曲约束支撑(RBRB),其具有更换方便、只需更换耗能段核心单元即可恢复使用功能等特点。本文运用有限元软件ABAQUS对其进行... 针对传统屈曲约束支撑结构在震后修复困难、需要整体更换等问题,本文根据“定点屈服”原理,提出一种新型可更换屈曲约束支撑(RBRB),其具有更换方便、只需更换耗能段核心单元即可恢复使用功能等特点。本文运用有限元软件ABAQUS对其进行数值模拟计算,主要研究了RBRB的抗震性能并分析不同开孔形式对RBRB抗震性能的影响,研究结果表明:该RBRB构造合理,具有良好的耗能能力和抗疲劳性能,滞回曲线稳定;当核心单元的截面面积一定时,随着开孔排数的增加,RBRB的延性性能逐渐降低,但均能满足罕遇地震作用下支撑的大变形需求;RBRB开孔段芯材受压变形为压缩、弯曲与剪切组合的机制,随着开孔排数的增加,剪切变形越明显,剪切变形容易导致RBRB发生面内失稳;由于一排孔的RBRB延性性能与整体性能优于两排孔、三排孔,且考虑加工难度,减少开孔数量,建议采用一排孔的RBRB。 展开更多
关键词 屈曲约束支撑 可更换 开孔 有限元分析 滞回性能
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碟簧式自复位防屈曲支撑滞回性能数值模拟
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作者 张城 王敦强 《计算机辅助工程》 2024年第3期57-61,共5页
为研究碟簧式自复位防屈曲支撑(SC-BRB)的滞回性能,利用Abaqus对其进行有限元分析,得到SC-BRB的滞回性能。参照相关试验和理论分析模型,验证有限元模型的准确性。结果表明:SC-BRB的滞回曲线呈现出显著的“旗帜型”特征,具备良好的复位... 为研究碟簧式自复位防屈曲支撑(SC-BRB)的滞回性能,利用Abaqus对其进行有限元分析,得到SC-BRB的滞回性能。参照相关试验和理论分析模型,验证有限元模型的准确性。结果表明:SC-BRB的滞回曲线呈现出显著的“旗帜型”特征,具备良好的复位效果和耗能能力;碟簧初始预压力越大,支撑的复位效果越好。 展开更多
关键词 自复位系统 防屈曲支撑 滞回性能 数值模拟 ABAQUS 有限元模型
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超大和罕遇地震下水工框架结构性能及其减震的对比
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作者 姜坤 杨青顺 《青海大学学报》 2024年第4期78-85,共8页
为了解水工框架结构在超大和罕遇地震下的破坏特征及防屈曲支撑对该结构抗震性能的改善效果,以某工程的水工框架结构为例,利用MSC Marc建立有限元模型,对土耳其7.8级地震和罕遇地震下水工框架结构的性能及防屈曲支撑对水工框架结构抗震... 为了解水工框架结构在超大和罕遇地震下的破坏特征及防屈曲支撑对该结构抗震性能的改善效果,以某工程的水工框架结构为例,利用MSC Marc建立有限元模型,对土耳其7.8级地震和罕遇地震下水工框架结构的性能及防屈曲支撑对水工框架结构抗震性能的改善效果进行了对比分析。结果表明:(1)在土耳其地震作用下,水工框架结构的楼层位移、层间位移角及大梁挠度较罕遇地震下大幅增加,梁柱节点新增塑性铰,结构破坏加剧。(2)防屈曲支撑对罕遇地震下水工框架结构抗震性能的改善效果明显,启闭大梁的挠度满足了规范的限值。(3)防屈曲支撑对土耳其地震下水工框架结构抗震性能的改善效果不佳。研究结果可为罕遇地震下利用防屈曲支撑改善水工框架结构抗震性能提供数据参考。 展开更多
关键词 水工框架结构 土耳其地震 罕遇地震 有限元模型 防屈曲支撑
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梁式桥桥墩计算长度系数研究
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作者 董佳霖 黄亮 +1 位作者 徐伟杰 包江磊 《浙江交通职业技术学院学报》 CAS 2024年第1期13-18,65,共7页
桥墩计算长度系数是影响桥墩设计的一个重要参数,值的取值过小会造成结构设计不安全,取值过大会造成设计不经济。本文考虑相邻桥墩抗推刚度与支座水平刚度对墩顶弹性约束的影响,从理论分析角度提出了桥墩计算长度系数的求解方法,并结合... 桥墩计算长度系数是影响桥墩设计的一个重要参数,值的取值过小会造成结构设计不安全,取值过大会造成设计不经济。本文考虑相邻桥墩抗推刚度与支座水平刚度对墩顶弹性约束的影响,从理论分析角度提出了桥墩计算长度系数的求解方法,并结合有限元模型,利用欧拉公式中的临界荷载与桥墩计算长度系数的关系,对比分析理论解与有限元模型计算的差异。此外本文还探讨了墩高、墩径及桥跨布置形式对梁式桥桥墩计算长度系数的影响和变化规律,为相似桥墩计算长度系数的取值及桥墩设计提供了依据。 展开更多
关键词 计算长度系数 临界荷载 有限元分析法 墩顶约束刚度
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极限搭接长度下约束浆锚连接的弹簧-梁单元模型R参数研究
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作者 周文君 聂红鑫 +1 位作者 王璇 李令令 《沈阳理工大学学报》 CAS 2024年第5期83-90,96,共9页
为保证“弹簧-梁单元”模型能够可靠模拟约束浆锚连接粘结破坏前受力,选取文献中的约束浆锚连接试验试件,应用“弹簧-梁单元”模型对其进行有限元建模,并严格按照文献中方式加载,调整圆截面梁单元半径R参数值,通过模拟计算得到与试验接... 为保证“弹簧-梁单元”模型能够可靠模拟约束浆锚连接粘结破坏前受力,选取文献中的约束浆锚连接试验试件,应用“弹簧-梁单元”模型对其进行有限元建模,并严格按照文献中方式加载,调整圆截面梁单元半径R参数值,通过模拟计算得到与试验接近的结果,分析影响R参数变化的因素。研究结果表明:R值受加载形式、搭接钢筋直径及搭接长度、螺旋箍筋配筋形式影响极小;恰当选择R参数是准确模拟约束浆锚连接粘结破坏前受力的关键,工程应用中确定某种浆锚连接节点R参数时仅需考虑灌浆料强度和预留孔道直径两个因素。 展开更多
关键词 约束浆锚 弹簧-梁单元 粘结破坏 有限元
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位移放大型自复位防屈曲支撑滞回性能分析与数值模拟
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作者 张路平 尚朝阳 +2 位作者 陈麒丞 张浩宇 鲁军凯 《黑龙江交通科技》 2024年第4期122-125,130,共5页
提出一种位移放大型自复位防屈曲支撑,通过Abaqus有限元软件建立数值模型,研究支撑滞回性能、自复位特性以及耗能能力。结果表明:该位移放大型自复位防屈曲支撑具有较好的滞回性能、耗能能力及自复位特性。该支撑的承载力受自复位系统... 提出一种位移放大型自复位防屈曲支撑,通过Abaqus有限元软件建立数值模型,研究支撑滞回性能、自复位特性以及耗能能力。结果表明:该位移放大型自复位防屈曲支撑具有较好的滞回性能、耗能能力及自复位特性。该支撑的承载力受自复位系统刚度影响较大,耗能能力受预拉力影响较小,当预拉力水平较低时,提高预拉力可以大幅提高支撑的复位性能。 展开更多
关键词 位移放大 自复位防屈曲支撑 预应力 有限元分析 滞回性能
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联塔斜拉桥大吨位屈曲约束支撑设计研究
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作者 王伟 王朝 刘鹏飞 《世界桥梁》 北大核心 2024年第6期80-86,共7页
桑园子黄河大桥为主跨328 m的分幅联塔斜拉桥,位于抗震设防烈度8度的高烈度地震区,联塔共用基础和承台,横向地震作用下联塔同向运动后产生竖向相对位移,联塔间需要能提供较大连接刚度与耗能能力的连接装置。针对联塔结构的耗能减震需求... 桑园子黄河大桥为主跨328 m的分幅联塔斜拉桥,位于抗震设防烈度8度的高烈度地震区,联塔共用基础和承台,横向地震作用下联塔同向运动后产生竖向相对位移,联塔间需要能提供较大连接刚度与耗能能力的连接装置。针对联塔结构的耗能减震需求,提出基于屈曲约束支撑(BRB)的阻尼耗能解决方案,在联塔间设置多套交叉布置的BRB形成多个阻尼器对,通过轴向拉伸与压缩协同发挥耗能能力。联塔结构竖向最大承载力要求达9450 t,设计制作大吨位足尺BRB试件,并进行有限元分析与力学性能试验,研究BRB试件屈服承载力、屈服位移、弹性刚度、极限位移、耗能能力及疲劳性能等。结果表明:BRB各项指标均表现良好,力学性能满足设计及标准要求,具有良好的拉压均匀性与塑性变形能力,耗能率较高。 展开更多
关键词 联塔斜拉桥 屈曲约束支撑 大吨位 力学性能 屈服承载力 弹性刚度 有限元法 足尺试验
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三重钢管防屈曲支撑滞回性能影响因素分析
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作者 王艳春 《山西建筑》 2024年第22期49-54,共6页
为给三重钢管防屈曲支撑及此类自复位防屈曲支撑的设计提供一定的设计依据,文章采用ABAQUS软件建立了三重钢管防屈曲支撑的有限元模型,并验证了建模方法的正确性,在此基础上研究了该类防屈曲支撑的受力机理,并分析了约束比、长细比、核... 为给三重钢管防屈曲支撑及此类自复位防屈曲支撑的设计提供一定的设计依据,文章采用ABAQUS软件建立了三重钢管防屈曲支撑的有限元模型,并验证了建模方法的正确性,在此基础上研究了该类防屈曲支撑的受力机理,并分析了约束比、长细比、核芯管的径厚比和间隙等参数对其承载力和滞回耗能性能的影响。研究结果表明,约束比对三重钢管防屈曲支撑的稳定性能影响较大,约束比不应小于1.58;核芯管的径厚比不大于22时,该类防屈曲支撑的滞回耗能能力较好;长细比对该类防屈曲支撑的刚度和稳定性能影响较大;建议其间隙取值为1 mm~2 mm。 展开更多
关键词 三重钢管防屈曲支撑 有限元分析 滞回性能 承载力 稳定性能
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Second Generation Wavelet Finite Element and Rotor Cracks Quantitative Identification Method 被引量:3
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作者 CHEN Xuefeng LI Bing HE Yuming HE Zhengjia 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2010年第2期195-199,共5页
The presence of cracks in the rotor is one of the most dangerous and critical defects for rotating machinery. Defect of fatigue cracks may lead to long out-of-service periods, heavy damages of machines and severe econ... The presence of cracks in the rotor is one of the most dangerous and critical defects for rotating machinery. Defect of fatigue cracks may lead to long out-of-service periods, heavy damages of machines and severe economic consequences. With the method of finite element, vibration behavior of cracked rotors and crack detection was received considerable attention in the academic and engineering field. Various researchers studied the response of a cracked rotor and most of them are focused on the crack detection based on vibration behavior of cracked rotors. But it is often difficult to identify the crack parameters quantitatively. Second generation wavelets (SGW) finite element has good ability in modal analysis for singularity problems like a cracked rotor. Based on the fact that the feature of SGW could be designed depending on applications, a multiresolution finite element method is presented. The new model of SGW beam element is constructed. The first three natural frequencies of the rotor with different crack location and size were solved with SGW beam elements, and the database for crack diagnosis is obtained. The first three metrical natural frequencies are employed as inputs of the database and the intersection of the three frequencies contour lines predicted the normalized crack location and size. With the Bently RK4 rotor test rig, rotors with different crack location and size are tested and diagnosed. The experimental results denote the cracks quantitative identification method has higher identification precision. With SGW finite element method, a novel method is presented that has higher precision and faster computing speed to identify the crack location and size. 展开更多
关键词 second generation wavelet finite element fault diagnosis CRACK
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On conversion of plastic work to heat during plastic deformation of tin-lead alloy and mild steel 被引量:1
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作者 李文亚 李京龙 高大路 《China Welding》 EI CAS 2010年第2期17-22,共6页
The temperature rise caused by plastic deformation during the quick upsetting of tin-lead alloy and mild steel was investigated via experiments and numerical simulations aiming at a better understanding of the heat ge... The temperature rise caused by plastic deformation during the quick upsetting of tin-lead alloy and mild steel was investigated via experiments and numerical simulations aiming at a better understanding of the heat generation mechanism in friction welding. The results show that the compression amount and deformation temperature influence significantly the temperature rise during the upsetting of tin-lead alloy. The temperature rise increases with increasing the compression but decreases with increasing the deformation temperature. The simulation results are in good agreement with the experimental inspection for Sn63A alloy. The simulation results of mild steel present a similar tendency with tin-lead alloy. Moreover, the temperature rise of mild steel at elevated temperatures is comparable to that of tin-lead alloy at low temperatures. 展开更多
关键词 plastic deformation finite element analysis friction welding heat generation tin-lead alloy
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Mechanical Properties of Soil-Rock Mixture Filling in Fault Zone Based on Mesostructure
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作者 Mei Tao Qingwen Ren +2 位作者 Hanbing Bian Maosen Cao Yun Jia 《Computer Modeling in Engineering & Sciences》 SCIE EI 2022年第8期681-705,共25页
Soil-rock mixture(SRM)filling in fault zone is an inhomogeneous geomaterial,which is composed of soil and rock block.It controls the deformation and stability of the abutment and dam foundation,and threatens the long-... Soil-rock mixture(SRM)filling in fault zone is an inhomogeneous geomaterial,which is composed of soil and rock block.It controls the deformation and stability of the abutment and dam foundation,and threatens the long-term safety of high arch dams.To study the macroscopic and mesoscopic mechanical properties of SRM,the development of a viable mesoscopic numerical simulation method with a mesoscopic model generation technology,and a reasonable parametric model is crucially desired to overcome the limitations of experimental conditions,specimen dimensions,and experiment fund.To this end,this study presents a mesoscopic numerical method for simulating the mechanical behavior of SRM by proposing mesoscopic model generation technology based on its mesostructure features,and a rock parameter model considering size effect.The validity and rationality of the presented mesoscopic numerical method is experimentally verified by the triaxial compression tests with different rock block contents(RBC).The results indicate that the rock block can increase the strength of SRM,and it is proved that the random generation technique and the rock parameter model considering size effect are validated.Furthermore,there are multiple failure surfaces for inhomogeneous geomaterial of SRM,and the angle of the failure zone is no longer 45◦.The yielding zones of the specimen are more likely to occur in thin sections of soil matrix isolated by blocks with the failure path avoiding the rock block.The proposed numerical method is effective to investigate the meso-damage mechanism of SRM. 展开更多
关键词 Soil-rock mixture(SRM) triaxial compression tests random generation technique MESOSTRUCTURE rock parameter model size effect finite element method
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