With the rapid development of the city, it is necessar</span><span style="font-family:Verdana;">y to obtain geological information within 500 meters. Electrical prospecting is not only low cost a...With the rapid development of the city, it is necessar</span><span style="font-family:Verdana;">y to obtain geological information within 500 meters. Electrical prospecting is not only low cost and simple operation, but also solves the problem of insufficient drilling density in </span><span style="font-family:Verdana;">a </span><span style="font-family:Verdana;">survey</span><span style="font-family:Verdana;">. However, due to the dense urban buildings and strong electromagnetic interference, it is difficult for traditional electrical instruments to obtain effective data</span><span style="font-family:Verdana;">.</span><span style="font-family:""> </span><span style="font-family:Verdana;">An </span><span style="font-family:Verdana;">anti-interference electrical method instrument is designed.</span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">In the application test of Tongzhou</span><span style="color:black;font-family:Verdana;"> core area in Beijing, the resistivity sounding data collected by </span></span><span style="font-family:"color:black;"><span style="font-family:Verdana;">anti-interference</span><span style="font-family:Verdana;"> electrical method </span><span style="font-family:Verdana;">instrument</span><span style="font-family:Verdana;"> is stable and reliable;inversion results of sounding are basically consistent with borehole data;</span><span style="font-family:Verdana;">the known Zhangjiawan fault and Yaoxinzhuang fault are obvious;basement karst collapse area inferred is basically coincident with the historical collapse area. It is proved that the anti-interference electrical </span><span style="font-family:Verdana;">method</span><span style="font-family:Verdana;"> instrument is effective and can be applied to the geological survey of underground space in other cities.展开更多
An inverse problem of elastica of a variable-arclength beam subjected to a concentrated load is investigated. The beam is fixed at one end, and can slide freely over a hinge support at the other end. The inverse probl...An inverse problem of elastica of a variable-arclength beam subjected to a concentrated load is investigated. The beam is fixed at one end, and can slide freely over a hinge support at the other end. The inverse problem is to determine the value of the load when the deflection of the action point of the load is given. Based on the elasitca equations and the elliptic integrals, a set of nonlinear equations for the inverse problem are derived, and an analytical solution by means of iterations and Quasi-Newton method is presented. From the results, the relationship between the loads and deflections of the loading point is obtained.展开更多
This paper presents a hybrid model reliability analysis method based on the damped Newton method with both random and interval variables to solve the hybrid structure reliability problem.The method combines an outer i...This paper presents a hybrid model reliability analysis method based on the damped Newton method with both random and interval variables to solve the hybrid structure reliability problem.The method combines an outer iterative solution and inner layer numerical calculation.In the outer iteration,the method seeks an optimized solution to the interval variable iterative by adding the boundary constraint condition based on the damped Newton optimization theory.In the inner layer solution,the method first reduces the dimension of the random variable through the dimension reduction method,then obtains the first four-order central moment of the function through the application of the Taylor expansion method,and finally calculates the reliability index of the structure according to the fourth-order moment calculation structure of the function.The results of a numerical example and an engineering ten-rod truss structure show that the proposed method can effectively solve the random-interval hybrid reliability problem and has better calculation accuracy than that of the two-layer iterative method.展开更多
文摘With the rapid development of the city, it is necessar</span><span style="font-family:Verdana;">y to obtain geological information within 500 meters. Electrical prospecting is not only low cost and simple operation, but also solves the problem of insufficient drilling density in </span><span style="font-family:Verdana;">a </span><span style="font-family:Verdana;">survey</span><span style="font-family:Verdana;">. However, due to the dense urban buildings and strong electromagnetic interference, it is difficult for traditional electrical instruments to obtain effective data</span><span style="font-family:Verdana;">.</span><span style="font-family:""> </span><span style="font-family:Verdana;">An </span><span style="font-family:Verdana;">anti-interference electrical method instrument is designed.</span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">In the application test of Tongzhou</span><span style="color:black;font-family:Verdana;"> core area in Beijing, the resistivity sounding data collected by </span></span><span style="font-family:"color:black;"><span style="font-family:Verdana;">anti-interference</span><span style="font-family:Verdana;"> electrical method </span><span style="font-family:Verdana;">instrument</span><span style="font-family:Verdana;"> is stable and reliable;inversion results of sounding are basically consistent with borehole data;</span><span style="font-family:Verdana;">the known Zhangjiawan fault and Yaoxinzhuang fault are obvious;basement karst collapse area inferred is basically coincident with the historical collapse area. It is proved that the anti-interference electrical </span><span style="font-family:Verdana;">method</span><span style="font-family:Verdana;"> instrument is effective and can be applied to the geological survey of underground space in other cities.
基金The project supported by the National Natural Science Foundation of China(10272011)
文摘An inverse problem of elastica of a variable-arclength beam subjected to a concentrated load is investigated. The beam is fixed at one end, and can slide freely over a hinge support at the other end. The inverse problem is to determine the value of the load when the deflection of the action point of the load is given. Based on the elasitca equations and the elliptic integrals, a set of nonlinear equations for the inverse problem are derived, and an analytical solution by means of iterations and Quasi-Newton method is presented. From the results, the relationship between the loads and deflections of the loading point is obtained.
基金supported by the National Natural Science Foundation of China(No.51775230)。
文摘This paper presents a hybrid model reliability analysis method based on the damped Newton method with both random and interval variables to solve the hybrid structure reliability problem.The method combines an outer iterative solution and inner layer numerical calculation.In the outer iteration,the method seeks an optimized solution to the interval variable iterative by adding the boundary constraint condition based on the damped Newton optimization theory.In the inner layer solution,the method first reduces the dimension of the random variable through the dimension reduction method,then obtains the first four-order central moment of the function through the application of the Taylor expansion method,and finally calculates the reliability index of the structure according to the fourth-order moment calculation structure of the function.The results of a numerical example and an engineering ten-rod truss structure show that the proposed method can effectively solve the random-interval hybrid reliability problem and has better calculation accuracy than that of the two-layer iterative method.
