三种高程传递方法的精度分析     

王岩  岳建平  马保卫  陈铁鑫 《北京测绘》2005,(1):20-24

通过试验对悬挂钢尺、GPS测高和全站仪垂直测高三种高程传递方法进行了理论分析与精度比较,并讨论了各种方法在实际应用中的优点与局限性。  相似文献   

大型钢结构变形测试方法的研究与实践     

潘国荣 《测绘信息与工程》2005,30(3):45-47

介绍了精密全站仪进行结构测试的原理和方法,通过对某大型游泳跳水馆钢结构网架在张拉和加载试验中的变形测量实践,证明其具有作业简便、能够全面反映结构变形情况之优点,且精度较高,成果可靠。  相似文献   

Multi‐objective optimal design of FLC driven hybrid mass damper for seismically excited structures     

A. S. Ahlawat  A. Ramaswamy 《地震工程与结构动力学》2002,31(7):1459-1479

Structural vibration control using active or passive control strategy is a viable technology for enhancing structural functionality and safety against natural hazards such as strong earthquakes and high wind gusts. Both the active and passive control systems have their limitations. The passive control system has limited capability to control the structural response whereas the active control system depends on external power. The power requirement for active control of civil engineering structures is usually quite high. Thus, a hybrid control system is a viable solution to alleviate some of the limitations. In this paper a multi‐objective optimal design of a hybrid control system for seismically excited building structures has been proposed. A tuned mass damper (TMD) and an active mass driver (AMD) have been used as the passive and active control components of the hybrid control system, respectively. A fuzzy logic controller (FLC) has been used to drive the AMD as the FLC has inherent robustness and ability to handle the non‐linearities and uncertainties. The genetic algorithm has been used for the optimization of the control system. Peak acceleration and displacement responses non‐dimensionalized with respect to the uncontrolled peak acceleration and displacement responses, respectively, have been used as the two objectives of the multi‐objective optimization problem. The proposed design approach for an optimum hybrid mass damper (HMD) system, driven by FLC has been demonstrated with the help of a numerical example. It is shown that the optimum values of the design parameters of the hybrid control system can be determined without specifying the modes to be controlled. The proposed FLC driven HMD has been found to be very effective for vibration control of seismically excited buildings in comparison with the available results for the same example structure but with a different optimal absorber. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   

Study of a semi‐active stiffness damper under various earthquake inputs     

S. L. Djajakesukma  B. Samali  H. Nguyen 《地震工程与结构动力学》2002,31(10):1757-1776

Semi‐active stiffness damper (SASD) is one of many semi‐active control systems with the capability to mitigate the dynamic response using only a small amount of external power. The system consists of a hydraulic damper connected to the bracing frame in a selected story unit. In this paper, study of a SASD in two building models of five‐stories under four benchmark earthquake records is reported. The purpose of this study is to evaluate the effectiveness of the control system against structure type and varying earthquake inputs. Various control laws are chosen to work with SASD, such as: resetting control, switching control, linear quadratic regulator (LQR) and modified LQR, and the results are compared with no control and passive control cases. Numerical results show that the use of a SASD is effective in reducing seismic responses. Control effectiveness is dependent on the type of structure and earthquake excitation. Passive control is less effective than other control cases as expected. Resetting control, switching control and LQR generally perform similarly in response reduction. While modified LQR is more efficient and robust compared with other control algorithms. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   

耗能减震结构的受力分析与层间弹塑性变形简化计算方法   总被引：3，自引：0，他引：3  

吴波  郭安薪  李惠  王光远 《地震工程与工程振动》2002,22(2):101-107

本文研究了安装粘弹性耗能器结构在常遇地震作用下层间最大剪力的分配情况 ,给出了层间最大剪力在结构构件与耗能器之间按刚度分配原则进行假想分配后 ,所得假想层间构件力与层间最大构件力之间的关系 ,以及假想层间附加力与层间最大附加力之间的关系 ,探讨了罕遇地震作用下安装粘弹性耗能器结构与安装软钢耗能器结构的层间弹塑性变形简化计算方法。  相似文献   

可调滞回模型的磁流变阻尼器及其试验   总被引：5，自引：0，他引：5  

杨飓  关新春  欧进萍 《地震工程与工程振动》2002,22(2):115-120

本文在现在磁流变阴尼器性能研究的基础上，提出了可调滞回模型的磁流变阻尼器及其试验方法，并进行理论、试验及算例分析。首先，根据恒定电流下磁流变阻尼器的阻尼力滞力特性，利用磁流变材料特性的电流（即磁场）可控特点，建立了变电流下的阻尼力滞回模型；其次，在中通过电路板控制外加电流与装置变形间的函数关系，实现了变电流调节的阻尼力滞回模型；最后，将磁流变阻尼器与橡胶隔震装置结合，形成智能磁流变隔夺装置，并对一个单自由度隔震结构进行了数值仿真分析。  相似文献   

高层钢框架-支撑结构二阶非线性随机地震响应分析   总被引：1，自引：0，他引：1  

陈兰  汤海波  梁启智 《地震工程与工程振动》2002,22(3):170-174

针对常用的高层钢框架－支撑结构，考虑材料非线性和几何非线性，建立了框架部分、支撑部分的二阶动力分析模型。用等效线性方法对结构进行非线性随机地震响应分析，结合工程算例，论述不同场地土、不同层数、不同支撑情况下，二阶效应对结构地震响应统计量的影响。  相似文献   

薄钢板剪力墙抗震性能试验研究   总被引：15，自引：6，他引：15  

苏幼坡  刘英利  王绍杰 《地震工程与工程振动》2002,22(4):81-84

通过4个薄钢板剪力墙和1个钢筋混凝土框架的试验，研究了薄钢板剪力墙在低周往复荷载作用下的刚度、承载力、延性和耗能性能。试验表明，利用薄钢板剪力墙在低周往复荷载作用下的刚度、承载力、延性和耗能性能。试验表明，利用薄钢板剪力墙作为抗侧力构件是可行的。在钢筋混凝土框架中设置薄钢板可有效地增加刚度，承载力和耗能性能。  相似文献   

铅橡胶复合阻尼器的性能试验研究   总被引：4，自引：0，他引：4  

刘冰  周云  邓雪松  徐赵东 《地震工程与工程振动》2002,22(5):105-114

介绍作者提出的铅橡胶复合阻尼器的构造与耗能原理，通过不同形状，不同大小铅心的8个铅橡胶复合阻尼器的循环荷载试验，研究了频率、应变幅值、循环次数、铅芯直径、竖向压力等对铅橡胶复合阻尼器的影响规律。研究结果表明，铅橡胶复合阻尼器工作性能稳定，耗能性能和抗疲劳性能好。  相似文献   

ISO-834标准火灾作用后钢管混凝土的轴压刚度和抗弯刚度   总被引：4，自引：1，他引：4  

霍静思  韩林海 《地震工程与工程振动》2002,22(5):143-151

火灾后钢管混凝土的轴压刚度和抗弯刚度是钢管混凝土结构变形性能和抗震分析的重要指标，也是火灾后钢管混凝土修复和加固的重要依据之一，本文利用数值方法计算了标准火灾作用后钢管混凝土轴压构件和纯弯构件荷载-变形关系曲线，分析了受火时间、材料强度、含钢率、截面尺寸等因素的影响规律，最后推导了标准火灾作用后钢管混凝土轴压刚度和抗弯刚度的简化计算公式，所得结果可供有关钢管混凝土结构工程设计时参考。  相似文献