High-speed video measurement method for progressive collapse of latticed shell structure

A technology of video measurement and reticulated shell, which is applied in the field of civil engineering, can solve the problems of the influence of experimental results, the limited range of contact displacement measurement, and the inability to accurately measure spatial displacement results, etc.

Active Publication Date: 2017-12-01
TONGJI UNIV
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Problems solved by technology

During the continuous collapse of the reticulated shell, neither the traditional contact sensor nor the conventional video measurement scheme can measure the internal points of the reticulated shell structure. The reasons are as follows: (1) The spherical nodes will have a large Displacement changes, and the range of the contact displacement meter is limited, which is prone to damage; (2) The contact sensor will increase the weight of the reticulated shell model, which will affect the experimental results; (3) The contact sensor can only measure the displacement of the node surface , but cannot measure the displacement of the center of the node sphere; (4) When the reticulated shell collapses, each node will not only have a vertical displacement but also a horizontal displacement in space, and the displacement meter or accelerometer that can only provide one-way displacement It is simply impossible to accurately measure the spatial displacement results of nodes

Method used

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  • High-speed video measurement method for progressive collapse of latticed shell structure
  • High-speed video measurement method for progressive collapse of latticed shell structure
  • High-speed video measurement method for progressive collapse of latticed shell structure

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Embodiment

[0041] 1. Experiment introduction

[0042] The single-layer reticulated shell structure model is as follows figure 1 shown. This model is the most common Kewitte reticulated shell, and its internal force will be evenly distributed at each spherical node and member. In view of the limitations of the experimental environment, manufacturing process, and mechanical conditions, the diameter of the reticulated shell model is designed to be 4.2m. The model consists of 37 welded nodal balls and 132 connecting rods, and these welded nodal balls with a diameter of 60 mm are used to connect rods and counterweights. At the beginning of the experiment, the rupture of the reticulated shell will trigger the continuous collapse of the entire structure. In the process of its collapse, it is necessary to accurately measure the center displacement of each welded node sphere. Therefore, this paper designs a special artificial marker and related analysis algorithm to solve the above-mentioned ...

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Abstract

The invention relates to a high-speed video measurement method for progressive collapse of a latticed shell structure. The high-speed video measurement method includes the steps of (1), arranging multiple high-speed cameras above a latticed shell model; (2), performing spherical-surface fitting to obtain initial three-dimensional coordinates of the center of sphere of each spherical node; (3), building a local object space coordinate system and distributing target point marks corresponding to the spherical nodes on the latticed shell model; (4), acquiring elements of exterior orientation of the cameras, the initial three-dimensional coordinates of the target point marks, and establishing fixed spatial relationship between the marks and the spherical nodes; (5), starting a latticed shell breaking device to realize progressive collapse of the latticed shell, and synchronously acquiring the image data about the collapse of the latticed shell through the high-speed cameras; (6), acquiring three-dimensional coordinates of the target point marks corresponding to centers of spheres of the spherical nodes, and carrying out coordinate conversion to obtain the three-dimensional coordinates of the center of sphere of each spherical node to finally obtain three-dimensional time history displacement of the center of the sphere of the spherical node. Compared with the prior art, the high-speed video measurement method has the advantages of high convenience in measurement of spherical center coordinates in a non-contact way, high precision, high frequency and the like.

Description

technical field [0001] The invention relates to the field of civil engineering, in particular to a high-speed video measurement method for continuous collapse of reticulated shell structures. Background technique [0002] In the field of civil engineering, the dynamic load measurement task of continuous collapse of structures is a technical problem. In the field of video measurement, many scholars have conducted in-depth research and formed unique measurement schemes. However, their methods can only directly observe the surface points of the structure, but cannot measure the internal points of the structure. [0003] In recent years, photogrammetry technology has been widely used in material testing and structural monitoring, and the resulting video measurement technology can measure the three-dimensional spatial shape changes of target objects in a non-contact method. During the continuous collapse of the reticulated shell, neither the traditional contact sensor nor the co...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01C11/36
CPCG01C11/00G01C11/36
Inventor 童小华高飒陈鹏叶真谢欢刘世杰杜莉
Owner TONGJI UNIV
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