A hybrid method is proposed to properly identify multiple damages for plate structures in this work. In the stage of damage localization, singular value decomposition （SVD） is applied to reveal singularities in moda...A hybrid method is proposed to properly identify multiple damages for plate structures in this work. In the stage of damage localization, singular value decomposition （SVD） is applied to reveal singularities in modal shapes, and hence to detect the damage locations. In the stage of damage quantification, based on the detected location information ant colony optimization （ACO） algorithm is introduced to estimate damage severity by searching for damage evaluation database, which reveals the relationship between the natural frequencies and the damage severity. The modal shapes and the natural frequencies required in damage localization and quantification are obtained via the wavelet finite element method. The numerical simulation and experimental investigation are carried out to test the performance of the hybrid method for free aluminum plates with multiple damages. And the results indicate that the proposed method is effective to identify multiple damages of plate structures with reasonable precision.展开更多
Horizontal density variation is a structural phenomenon of non-veneer wood composites. The variation and distribution characteristics of horizontal density have impacts on the products properties. In this study, venee...Horizontal density variation is a structural phenomenon of non-veneer wood composites. The variation and distribution characteristics of horizontal density have impacts on the products properties. In this study, veneer strip simulated flake boards with 4 kinds of density distribution were made using a mat model. The density variation of the modeled mats was discussed, as well as the relationship between sample size and density variation. The effects of density and density distribution of non-veneer composites on the internal bond strength were analyzed. Result shows that the horizontal density of random formed particleboard follows normal distribution. Density has remarkable influence on internal bond strength (IB). Increasing density helps to improve IB at lower density stage, but has negative impacts on IB at higher density stage. Density variation between testing specimens depends on their sizes. Properly increasing specimen size can decrease the variation of the IBs.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.51475356)the National Key Basic Research Program of China(Grant No.2015CB057400)the Wenzhou Technologies R&D Program of China(Grant No.G20140047)
文摘A hybrid method is proposed to properly identify multiple damages for plate structures in this work. In the stage of damage localization, singular value decomposition （SVD） is applied to reveal singularities in modal shapes, and hence to detect the damage locations. In the stage of damage quantification, based on the detected location information ant colony optimization （ACO） algorithm is introduced to estimate damage severity by searching for damage evaluation database, which reveals the relationship between the natural frequencies and the damage severity. The modal shapes and the natural frequencies required in damage localization and quantification are obtained via the wavelet finite element method. The numerical simulation and experimental investigation are carried out to test the performance of the hybrid method for free aluminum plates with multiple damages. And the results indicate that the proposed method is effective to identify multiple damages of plate structures with reasonable precision.
文摘Horizontal density variation is a structural phenomenon of non-veneer wood composites. The variation and distribution characteristics of horizontal density have impacts on the products properties. In this study, veneer strip simulated flake boards with 4 kinds of density distribution were made using a mat model. The density variation of the modeled mats was discussed, as well as the relationship between sample size and density variation. The effects of density and density distribution of non-veneer composites on the internal bond strength were analyzed. Result shows that the horizontal density of random formed particleboard follows normal distribution. Density has remarkable influence on internal bond strength (IB). Increasing density helps to improve IB at lower density stage, but has negative impacts on IB at higher density stage. Density variation between testing specimens depends on their sizes. Properly increasing specimen size can decrease the variation of the IBs.
