排序方式: 共有24条查询结果,搜索用时 15 毫秒
1.
2.
3.
关于承受冲击压力的压杆的研究,各方面已经做了不少的理论分析和试验.本文讨论的压杆不仅承受轴向的冲击压力,而且同时受到横向的冲击荷载作用,我们以研究这种压杆的承载能力为主要目的.为了了解它的动力性能,故从弹性振动开始讨论,同时对其弹塑性振动也作扼要的分析.本文中假设:1)压杆的冲击压力的作用时间是比较长,压力波的传播和反射过程不予考虑.2)压杆具有初始偏心,主要研究它的横向振动.承受冲击压力的直杆的纵向振动不在本文讨论范围之内.3)变形超过弹性极限后压杆近似地作为具有一个塑性铰的刚塑性体系来处理 相似文献
4.
5.
6.
IntroductionServiceloads,environmentalandaccidentalactionsmaycausedamagetostructures .Whenthestructuraldamageissmalloritisintheinteriorofthestructure,itsdetectioncannotbedonevisually.Inspectionofexistingbuildingsandbridgesaftercatastrophicevents,suchasearthquakesandhurricanes,aswellasundernormaloperatingconditions ,isoftentimeconsumingandcostlybecausecriticalmembersandconnectionsareconcealedundercladdingandotherarchitecturaldecorations.Formanyimportantstructures,suchashospitals,firestations,mi… 相似文献
7.
The relative sensitivities of structural dynamical parameters were analyzed using a directive derivation method. The neural network is able to approximate arbitrary nonlinear mapping relationship, so it is a powerful damage identification tool for unknown systems. A neural network-based approach was presented for the structural damage detection. The combined parameters were presented as the input vector of the neural network, which computed with the change rates of the several former natural frequencies (C), the change ratios of the frequencies (R), and the assurance criterions of flexibilities ( A ). Some numerical simulation examples, such as, cantilever and truss with different damage extends and different damage locations were analyzed. The results indicate that the combined parameters are more suitable for the input patterns of neural networks than the other parameters alone. 相似文献
8.
9.
灰色系统模型在结构损伤识别中的应用 总被引:1,自引:0,他引:1
开发结构健康监测系统是结构损伤识别的一个重要课题。由于建筑结构具有很多不确定因素,通过模态分析识别结构损伤的精度很难保证。本文提出一种灰色系统模型应用于结构损伤识别的方法。建立频率变化率和刚度变化的灰色系统模型,把一阶单变量的灰色模型(M(1,1))作为频率变化率和刚度变化之间的系统,通过一阶单变量的灰色模型(M(1,1))预测来体现结构动力指纹的整体功能,确定频率变化率和刚度变化之间的关系变量。为了验证理论,对多种工况进行了框架结构模型的振动试验并对结果进行了分析。试验结果表明:对于层间剪切结构,通过测量结构频率变化,建立的灰色系统模型可以较准确地确定结构的损伤位置和损伤程度,并使识别精度得到有效提高。 相似文献
10.