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煤层脉动水力压裂动静态响应数值模型及求解 被引量:6
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作者 陆沛青 李根生 +3 位作者 黄中伟 宋先知 盛茂 贺振国 《岩土力学》 EI CAS CSCD 北大核心 2015年第5期1471-1480,共10页
煤层脉动水力压裂是一项大范围提高煤层渗透率的新技术,但针对脉动应力波在实际地层的传播、扰动规律研究较少。采用交错网格数高阶有限差分法,结合完全匹配层和准静态围压加载两种边界条件,建立了含围压无限大弹性地层脉动水力压裂动... 煤层脉动水力压裂是一项大范围提高煤层渗透率的新技术,但针对脉动应力波在实际地层的传播、扰动规律研究较少。采用交错网格数高阶有限差分法,结合完全匹配层和准静态围压加载两种边界条件,建立了含围压无限大弹性地层脉动水力压裂动静态响应数值模型,并研究了不同加载方式、频率、振幅、围压条件下煤层最小主应力峰值分布规律。研究表明:由于应力波传播及干涉效应,相同围压、振幅条件下脉动压裂增透扰动区域远大于准静态压裂;煤层增透面积随震源频率和振幅的增加而增大,振幅需要克服由围压控制的启动压力才能产生增透区;增透面积与地层主应力成反相关且最小主应力起主导作用,其由3.5 MPa下降至2.0 MPa时,增透面积最高可提升600%。模型可模拟准静态和脉动加载下煤层的力学响应,其结果可为优化脉动水力压裂工艺参数提供指导。 展开更多
关键词 煤层 水力压裂 交错网格 动静态响应 参数优化
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群桩的动静态响应
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作者 M.Novak H.Janes 卢应发 《土工基础》 1992年第A10期75-79,共5页
群桩对动、静态荷载的响应受到桩——土——桩之间相互作用的影响。采用静动态相互作用因子来研究小位移情况下群桩的响应。本文介绍群桩刚度和阻尼的封闭解表达式并说明动、静态相互作用的差异。人们对大位移下的群桩响应了解很少。文... 群桩对动、静态荷载的响应受到桩——土——桩之间相互作用的影响。采用静动态相互作用因子来研究小位移情况下群桩的响应。本文介绍群桩刚度和阻尼的封闭解表达式并说明动、静态相互作用的差异。人们对大位移下的群桩响应了解很少。文中介绍了承受水平向静荷载的群桩的现场试验。本文的目的,是要研究在大位移情况下群桩的性状,重点在于讨论桩间相互作用因子和群桩刚度随着位移增加而变化的情况。 展开更多
关键词 群桩 动静态响应 载荷
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激光冲击波加载AZ31B镁合金薄板动静态响应实验研究 被引量:6
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作者 印成 冯爱新 +5 位作者 曹宇鹏 何叶 庄绪华 陈风国 吕豫文 吴浩 《应用激光》 CSCD 北大核心 2014年第6期562-566,共5页
为分析激光冲击AZ31B镁合金薄板背面的动态响应与残余应力分布规律,采用PVDF贴片传感器对冲击波进行测量得到压电波形与动态应变响应曲线,X射线衍射仪对薄板背面冲击区域中心与其边界点冲击前后残余应力进行测量,结合冲击波的传播规律,... 为分析激光冲击AZ31B镁合金薄板背面的动态响应与残余应力分布规律,采用PVDF贴片传感器对冲击波进行测量得到压电波形与动态应变响应曲线,X射线衍射仪对薄板背面冲击区域中心与其边界点冲击前后残余应力进行测量,结合冲击波的传播规律,解释了应变变化对残余应力变化的影响。结果表明,冲击波从冲击区域向冲击区域外的传播过程中,能量衰减明显。动态应变响应曲线类似正弦曲线,冲击区域在弹塑性双波加载时动态应变骤然增高,随后波动上升,最终的静态应变呈现拉应变与检测出的残余应力变化规律相符,冲击区域边缘的动态应变响应相较冲击区域变化缓和,弹塑性双波的卸载与加载过程并未引起动态应变的大幅突变,静态应变变化不大与残余应力的变化规律一致。 展开更多
关键词 AZ31B镁合金 压电波形 动静态响应 残余应力
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基于光纤光栅技术的半刚性基层力学响应测试分析 被引量:6
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作者 张静 魏连雨 +2 位作者 马士宾 李娜 张奕杰 《传感技术学报》 CAS CSCD 北大核心 2016年第3期326-331,共6页
依托104国道改建项目,开展了光纤光栅传感器在半刚性基层动静态力学响应测试中的应用研究。通过测试静载和动载作用下半刚性基层底拉应变,分析静载作用下轴重对半刚性基层底拉应变的影响,以及动载作用下车速对半刚性基层底拉应变的影响... 依托104国道改建项目,开展了光纤光栅传感器在半刚性基层动静态力学响应测试中的应用研究。通过测试静载和动载作用下半刚性基层底拉应变,分析静载作用下轴重对半刚性基层底拉应变的影响,以及动载作用下车速对半刚性基层底拉应变的影响。研究表明,静载作用下半刚性基层底拉应变与荷载大小呈正比,且随荷载值增加拉应变增长率不断减小,当荷载较小时,基层承受大部分荷载,层底拉应变实测值大于理论值,随荷载的增加,实测值逐渐趋近理论值,即受力情况逐渐趋于结构整体受力;动载作用下,半刚性基层底拉应变与荷载大小呈正比,与车辆车速呈反比。测试结果表明光纤光栅传感器与半刚性基层协同变形良好,能较好地用于半刚性基层应变场的测试,应用前景广阔。 展开更多
关键词 道路工程 应变测试 光纤光栅传感技术 半刚性基层 静态力学响应
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Dynamic characteristics of coal specimens with varying static preloading levels under low-frequency disturbance load
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作者 WEN Xiao-ze FENG Guo-rui +5 位作者 GUO Jun YU Lu-yang QIAN Rui-peng ZHANG Jie ZHANG Peng-fei FENG Wen-ming 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第8期2644-2657,共14页
The mechanical properties of residual coal pillars under the influence of upward mining disturbances significantly affect the safety of residual mining activities on working faces.This study conducted low-frequency di... The mechanical properties of residual coal pillars under the influence of upward mining disturbances significantly affect the safety of residual mining activities on working faces.This study conducted low-frequency disturbance dynamic uniaxial compression tests on coal specimens using a self-developed dynamic-static load coupling electro-hydraulic servo system,and studied the strength evolutions,surface deformations,acoustic emission(AE)characteristic parameters,and the failure modes of coal specimens with different static preloading levels were studied.The disturbance damage is positively correlated with the coal specimen static preload level.Specifically,the cumulative AE count rates of the initial accelerated damage stage for the coal specimens with static preloading level of 60%and 70%of the uniaxial compressive strength(UCS)were 2.66 and 3.19 times that of the 50%UCS specimens,respectively.Macroscopically,this behaviour manifested as a decrease in the compressive strength,and the mean strengths of the disturbance-damaged coal specimens with 60%and 70%of UCS static preloading decreased by 8.53%and 9.32%,respectively,compared to those of the specimens under pure static loading.The crack sources,such as the primary fissures,strongly control the dynamic response of the coal specimen.The difference between the dynamic responses of the coal specimens and that of dense rocks is significant. 展开更多
关键词 low-frequency disturbance dynamic response coal specimens static preloading level
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中承式钢筋混凝土吊杆拱桥健康监测研究分析 被引量:1
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作者 楚帅 《交通科技与管理》 2023年第12期39-41,共3页
文章结合某中承式钢筋混凝土吊杆拱桥的基本概况,使用MidasCivil专业建模软件对该桥梁进行建模分析,并通过该桥一期恒载、二期恒载、车辆荷载及温度荷载作用下的响应情况,进行动静态响应分析,实现对该桥的健康监测设计和对监测数据的分... 文章结合某中承式钢筋混凝土吊杆拱桥的基本概况,使用MidasCivil专业建模软件对该桥梁进行建模分析,并通过该桥一期恒载、二期恒载、车辆荷载及温度荷载作用下的响应情况,进行动静态响应分析,实现对该桥的健康监测设计和对监测数据的分析,评估了拱桥的安全性。 展开更多
关键词 健康监测 MidasCivil 动静态响应
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1.2m望远镜风载作用分析 被引量:15
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作者 周超 杨洪波 +1 位作者 吴小霞 张景旭 《红外与激光工程》 EI CSCD 北大核心 2011年第5期889-893,共5页
风载是影响地基大口径光电望远镜性能的重要因素之一,其作用会直接影响主次镜面型精度,引起望远镜指向误差,从而降低其成像精度和跟踪性能。为了研究风载对望远镜的影响程度,介绍了风载的概念,建立了风压力谱的数学模型。借助有限元法,... 风载是影响地基大口径光电望远镜性能的重要因素之一,其作用会直接影响主次镜面型精度,引起望远镜指向误差,从而降低其成像精度和跟踪性能。为了研究风载对望远镜的影响程度,介绍了风载的概念,建立了风压力谱的数学模型。借助有限元法,建立了1.2 m望远镜系统的有限元模型,分析了主镜在静态风载压力下的面型变化,以及望远镜系统在动态风载作用下的随机响应情况。计算出风载引起主镜镜面变形RMS值为0.65 nm,跟踪指向误差RMS值为0.015 6″。结果表明:风载影响在精度允许范围之内。 展开更多
关键词 望远镜 风载 有限元法 动静态响应
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基于Simulink的永磁同步电机控制策略仿真研究 被引量:3
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作者 黄宇 陈建国 《舰船电子工程》 2019年第12期106-110,共5页
针对传统永磁同步电机SPWM控制系统存在的直流母线电压利用率低,转矩脉动大等问题,研究了基于矢量控制(SVPWM)的永磁同步电机控制系统模型。详细分析了SVPWM控制中的参考电压扇区矢量判断模块、各扇区中各矢量作用时间模块、扇区矢量切... 针对传统永磁同步电机SPWM控制系统存在的直流母线电压利用率低,转矩脉动大等问题,研究了基于矢量控制(SVPWM)的永磁同步电机控制系统模型。详细分析了SVPWM控制中的参考电压扇区矢量判断模块、各扇区中各矢量作用时间模块、扇区矢量切换点确定模块和PWM脉冲信号产生模块的实现;同时,该系统采用矢量控制策略中的励磁电流id=0控制。在Matlab/Simulink平台上搭建了仿真模型,仿真结果表明:基于SVPWM控制方法下的永磁同步电机系统动态响应速度快,抗干扰能力强,仿真波形与理论分析一致,验证了该仿真实验平台的有效性。 展开更多
关键词 永磁同步电机 矢量控制 双环控制 动静态响应 SIMULINK
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Dynamic response and failure behavior of rock under static-dynamic loading 被引量:7
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作者 陈枫 马春德 徐纪成 《Journal of Central South University of Technology》 2005年第3期354-358,共5页
Dynamic response and failure behavior of rock under static-dynamic loading were studied. The effects of initial static load on the total energy dissipated during the failure process of specimen were analyzed. To simul... Dynamic response and failure behavior of rock under static-dynamic loading were studied. The effects of initial static load on the total energy dissipated during the failure process of specimen were analyzed. To simulate the engineering situation that in-situ rock experienced and obtain the dynamic loading with an intermediate strain rate, a low cycle fatigue load with the frequency from 0.5 to 5 Hz was adopted by servo-controlled Instron material testing system. The results show that the obtained strain rate increase with the increase of load frequency. The initial static load has great influence on both the energy and dynamic response of rock. Both the energy and the maximum failure load P_f decreases with the increase of initial static load. P_f under the static-dynamic loading is larger than that under only the static loading but less than that under only the dynamic loading. The load-displacement curves become nonlinear as the pre-added static load reaches the transition point which is about one third of static strength. With the increase of initial static load, Young’s modulus decreases and poisson ratio increases. It shows that rock has a lower strength and a tendency to soften under a higher initial static load. Rock may be broken more easily static-dynamic loading than under only the dynamic loading. The proposed method is useful in the investigation of constitutive relationship and failure behavior of rock under quasi-dynamic loading. 展开更多
关键词 dynamic response ROCK static-dynamic loading strain rate
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Effect of static transmission error on dynamic responses of spiral bevel gears 被引量:4
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作者 唐进元 胡泽华 +1 位作者 吴丽娟 陈思雨 《Journal of Central South University》 SCIE EI CAS 2013年第3期640-647,共8页
The effect of static transmission error on nonlinear dynamic response of the spiral bevel gear system combining with time-varying stiffness and backlash was investigated.Firstly,two different control equations of the ... The effect of static transmission error on nonlinear dynamic response of the spiral bevel gear system combining with time-varying stiffness and backlash was investigated.Firstly,two different control equations of the spiral bevel gear model were adopted,where the static transmission error was expressed in two patterns as predesigned parabolic function and sine function of transmission errors.The dynamic response,bifurcation map,time domain response,phase curve and Poincare map were obtained by applying the explicit Runge-Kutta integration routine with variable-step.A comparative study was carried out and some profound phenomena were detected.The results show that there are many different kinds of tooth rattling phenomena at low speed.With the increase of speed,the system enters into stable motion without any rattling in the region(0.72,1.64),which indicates that the system with predesigned parabolic function of transmission error has preferable capability at high speed. 展开更多
关键词 spiral bevel gear static transmission error dynamic response BIFURCATION
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Lateral static and dynamic characteristics of thin-walled box girder 被引量:1
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作者 甘亚南 周广春 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2009年第1期101-106,共6页
To analyze the static and dynamic behaviors of the thin-walled box girder in its lateral webs in consideration of shear lag effect and shear deformation, an approach based on the minimum potential principle is introdu... To analyze the static and dynamic behaviors of the thin-walled box girder in its lateral webs in consideration of shear lag effect and shear deformation, an approach based on the minimum potential principle is introduced in this paper. Both static and dynamic response equations as well as the corresponding natural boundary conditions of the box girder are deduced. Meanwhile, three generalized displacement functions: w (x) , U(x) and O(x) are employed and their differences in the calculus of variation are quantitatively investigated. The comparison of finite shell element results with analytical results of calculation examples validates the feasibility of the proposed approach. 展开更多
关键词 thin-walled box girder shear lag effect static and dynamic characteristics energy-variation principle
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