Engineering structure often produces the crack in the use of a certain year, the crack will decline the stiffness of structure which affects the safety of the structure and the vibration characteristics of structure. A method of identifying the crack damage from beam by using the vibration modal displacement component to strutting the damage identification was put forward, the finite element models of beam which no crack, different position and different depth were established, the damage displacement modal parameters of beams pre and post were calculated, the change rule that the displacement modals variation of transverse component and displacement modals rate of change of axial displacement difference along with the different of the cracks depth and position was analyzed., The calculations showed that the sensitive to the crack position and depth along the crack direction displacement modal transverse component variation and change rate of the axial displacement difference can be used as the basis for crack damage identification of beam.
Damage identification method of space rigid frame was based on change rate with the difference of the first axial modal, which applied to the model of space rigid frame on experiment. With extracting the experimental modal data to calculate the change rate with difference of the first axial model, the result shown that the change rate with difference of first axial model increased significantly in the injury site, and could identify well the damage location of single or multiple injuries, which was an ideal space frame damage labeled amount because of high sensitivity, less work of measure and calculation.
Structural crack damage will degrade its carrying capacity, and affect the security of the structure. Thus early detection of crack damage is a guarantee of the structure safety. Cracks can change the vibration characteristics of the structure, therefore we proposed a method of identifying the crack damage based on the vibration modal. Take both ends fixed beam as an example, through establish the finite element models of crack-free beam and the crack beam with different location and different depth, we calculate the displacement modal parameters of beam before and after the damage, analyze the variation law of displacement modal horizontal component of change and displacement modal Axial displacement difference rate of change varies with crack depth and location, results show that the variation of displacement modal horizontal component and the change rate of displacement modal Axial displacement difference along crack direction are sensitive to cracks location and depth, these can be used as a basis for identification of beam’s crack damage.
The finite element model of space rigid frame with no damage and damage were established by ANSYS and the physical model experiment was carried out. The damage identification methods include that variety rate of three-dimensional vibration mode, curvature mode, strain energy of element mode and axial mode shape difference. Consider identify result and measurement cost that the axial mode shape difference is a good label amount for three-dimension damage identification by vibration method and the single damage and combination damage could identified, which it was proved by the experiment result.
The finite element model of the combination bracket about solar collector was built and modal characteristics of the structure were analyzed. Wind speed time series was simulated in a given wind speed of the wind power spectrum by AR mode of linear filtering and fluctuating wind load time samples were got in each node on the windward side. The curve of load time series was took as the power input, and the wind-induced response of structures was calculated under random wind loads by the transient analysis. The results show that the large displacements appears on the edge of Collector components along horizontal and vertical direction in the case of fluctuating wind and the greater stress occurs in the joint of the cantilevered brackets connect and the upper end of the torque box, so it should be noted in the design of brackets of solar collector.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.