【作者】 祝德春；

【导师】 张方；

【作者基本信息】 南京航空航天大学 ， 工程力学， 2010， 硕士

【摘要】 以频域、时域法为代表的动态载荷识别技术得到了迅猛发展,若干识别技术已成功运用到航空、航天、机械等工程实际当中。近年来,逐渐发展了以神经网络、遗传算法和小波分析等技术与振动理论交叉融合的载荷识别新方法,冲击定位方法也随之兴起,但少有涉及一般性的载荷位置识别及其工程应用技术的研究。本文以线弹性梁和板为研究对象,探讨了动态载荷位置识别的频域和时域识别方法,并介绍了与之紧密相关的若干理论。首先,基于频响函数灵敏度分析的方法探讨了载荷识别响应测点选取准则;随后,对从实测振动信号中估计载荷个数的方法做了试探性研究。频域识别时,根据动态载荷识别频域法,分别由两组不同的振动响应识别出系统上所有虚拟激励位置处的两组当量动载荷,数值上相等两组当量动载荷对应的虚拟激励位置即为载荷真实作用位置,据此提出了动态载荷位置识别的最小判别系数法。时域识别时,对在采样时间内识别出的系统所有虚拟激励位置处的两组当量动载荷做差值运算,差值的最小均方根平均值对应的虚拟激励位置即为载荷的真实作用位置,据此提出了动态载荷位置识别的均值判别系数法。梁和板的仿真结果证明了识别方法的正确性。最后,对动态载荷位置识别技术做了实验验证,识别结果良好,证明了识别方法的正确性和工程应用可行性。更多还原

【Abstract】 Dynamic load identification technology maily in frequency domain and in time domain has be developed rapidly, some had been successfully used in to the area of aviation, aerospace and machinery and any other engeering structures. Some new method based on the cross-fusion between neural networks, genetic algorithms and wavelet analysis technology and the vibration theory this year, and the impact location method also under developing, but less research about the general method of load location identification and it’s application in engineering.In this paper, the technology of load location identification in frequency domain and in time domain had been introduced, some important theory related to the identification also is introduced.Discussion the general principles of the vibration response selected for identification based on the the sensitivity of the frequency response. Then, try some basic research of measurement of load number from the measured vibration signal at last.Based on the method of dynamic load identification in frequency domain, identification two group equivalent dynamic loads at all the virtual position by two different group vibration response, the location which the two equal loads corresponding to is the real position, all it’s the method of minimum discriminate coefficients. In the sample time, simulate the difference of the two group load, the location which the minmum RMS of the difference corresponding to be the real position, this method called the method of mean discriminant coefficients. Simulate result of the beam and the plate had explained the correctness of the method.At the end of this paper, an experiment had been made; the good identification result had explained the method’s correctness and feasibility in engineering application.更多还原