Qiqiang Chen^{1, *}, Xinxin Gan², Wei Huang¹, Jingjing Feng¹, H. Shim³

CMC-Computers, Materials & Continua, Vol.65, No.3, pp. 2201-2215, 2020, DOI:10.32604/cmc.2020.011191

Abstract Automatic road damage detection using image processing is an important aspect of road maintenance. It is also a challenging problem due to the inhomogeneity of road damage and complicated background in the road images. In recent years, deep convolutional neural network based methods have been used to address the challenges of road damage detection and classification. In this paper, we propose a new approach to address those challenges. This approach uses densely connected convolution networks as the backbone of the Mask R-CNN to effectively extract image feature, a feature pyramid network for combining multiple scales features, a region proposal network… More >

Alan Alonso-Rivers¹, Rolando Salgado-Estrada^2,*

Structural Durability & Health Monitoring, Vol.14, No.3, pp. 187-204, 2020, DOI:10.32604/sdhm.2020.010743

Abstract A dynamic simulation method for cracked structures is implemented to determine their dynamic response with the purpose of evaluating their structural behavior. The procedure makes possible the simulation of three-dimensional cracked structures. The excitation force is randomly generated to simulate wind gusts. It is assumed the structure remains in the elastic range, which allows for each mode that contributes to its dynamic response to be decoupled. The results indicate that the presence of damage causes changes in the modals parameters of the structure as accurate as other similar methods proposed for simpler structures. Therefore, it is concluded that the proposed… More >

Yanchao Yue^{1, *}, Tangbing Chen¹, Lingling Zhang¹, Moustafa Abdelsalam¹, Josephine Musanyufu¹

CMES-Computer Modeling in Engineering & Sciences, Vol.122, No.1, pp. 259-272, 2020, DOI:10.32604/cmes.2020.07218

Abstract Based on wave interference, a methodology to realize the total transmission phenomenon of SH0 waves is proposed in this paper. After a systematical theoretical investigation, an exact frequency of a flat plate consisting of another medium with finite length, is obtained, which is furthermore exemplified by the finite element method. This frequency is the same as the classical Fabry-Perot condition and dependent on the thickness of the material. It has been revealed that an SH0 wave, with its wavelength equal to twice of the length of another medium, can totally transmit across the medium without reflection. Especially when the impedance… More >

Gouravaraju Saipraneeth¹, Ranjan Ganguli²

Structural Durability & Health Monitoring, Vol.7, No.1&2, pp. 23-64, 2011, DOI:10.3970/sdhm.2011.007.023

Abstract In this paper, the effect of damage on mode shape related parameters of a beam is investigated. The damage is represented by a localized reduction in beam stiffness. The damage location and amount is varied using a finite element model of the beam to obtain the mode shapes. A beam which is simply supported at both ends is used for the numerical results. The periodic nature of the beam is exploited to obtain spatial Fourier coefficients of the mode shapes. As the damage location and size are varied, it is found that the Fourier coefficients also change and are found… More >

A. Likhith Reddy¹, Shirleen Charles¹, C. Bharathi Priya², G.V. Rama Rao², N. Gopalakrishnan^3,4 , A. Rama Mohan Rao³

Structural Durability & Health Monitoring, Vol.9, No.4, pp. 325-347, 2013, DOI:10.32604/sdhm.2013.009.325

Abstract Details of the investigations on an unexplored application of Electro Mechanical Impedance (EMI) technique using smart piezoelectric (PZT) sensors for damage detection of concrete shear wall structures under crack opening and closing is presented in this paper. The behavior and the ability of this method to detect damages, in a heterogeneous quasi-brittle material is studied for its effective utilization in structural health monitoring. The paper discusses the experimental investigations conducted on a concrete shear wall using PZT patches. Conductance data is acquired at different applied lateral displacements of shear wall. Damage index is calculated using Root Mean Square Deviation (RMSD),… More >

He Xufei¹, Deng Zhongmin², Song Zhitao¹

Structural Durability & Health Monitoring, Vol.8, No.3, pp. 193-208, 2012, DOI:10.32604/sdhm.2012.008.193

Abstract This paper describes an information optimizing scheme which is developed by integrating rough set and hierarchical data fusion. The novel structural damage indices are extracted using the information from different sources and then imported into probabilistic neural network (PNN) for classification and health assessment. In order to enhance the accuracy of diagnosis, results from separate PNN classification are fused to achieve comprehensive decision. Rough set is employed to decrease the spatial dimension of data. The predictive accuracy of optimizing scheme is demonstrated on a helicopter, taken as an example, with varied sensors, for multiple damage identification. More >

Shu Minakuchi¹, Tadahito Mizutani¹, Haruka Tsukamoto², Mayuko Nishio², Yoji Okabe³, Nobuo Takeda¹

Structural Durability & Health Monitoring, Vol.4, No.4, pp. 199-220, 2008, DOI:10.3970/sdhm.2008.004.199

Abstract The authors propose a technique to detect centimeter internal damages in large-scale composite structures, using an optical fiber network running throughout the structure. A Brillouin-based distributed strain sensing system with centimeter-order spatial resolution (pre-pump pulse Brillouin optical time domain analysis (PPP-BOTDA)) was utilized to detect residual non-uniform strain in the damaged area. First, Brillouin spectral response depending on the strain profile within the spatial resolution was revealed. The spectral response depending on strain non-uniformity was experimentally quantified with consideration of the general characteristics of the Brillouin gain spectrum. Then, the damage detection procedure was proposed, based on the spectral response.… More >

Jean-Jacques Sinou¹

Structural Durability & Health Monitoring, Vol.3, No.3, pp. 133-164, 2007, DOI:10.3970/sdhm.2007.003.133

Abstract This paper aims to establish a damage identification methodology, called the Frequencies' Ratio Surfaces Intersection method (FRSI-method), for predicting not only the location and depth of the crack but also the crack orientation in a circular cross section beam. Two new criterions %Δ_i^cracked and %ψ_i,j^cracked that consider only the ratio of the natural frequencies of the cracked beam are introduced and discussed in order to detect the crack parameters. In order to avoid worse diagnostic, it is demonstrated that a robust identification of crack location is possible by investigating the emergence of extra antiresonance peaks on Frequency Response… More >

Zhigang Guo, Zhi Sun

The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.2, pp. 61-62, 2011, DOI:10.3970/icces.2011.018.061

Abstract An efficient approach to identify multiple cracks in a slender beam using the frequency response function data is presented. It is formulated in a general form from the dynamic stiffness equation of motion for a structure and then applied to a slender beam. The cracks are modeled by rotational springs and the frequency response function is computed based on a spectral element model by the spectral finite element. The procedure gives a linear relationship explicitly between the changes of the measured frequency response function and crack parameters. The inverse problem is solved iteratively for the depths and locations of the… More >

Zhihai Xiang, Xiaowei Dai, Yao Zhang, Longqi Wang, Qiuhai Lu

The International Conference on Computational & Experimental Engineering and Sciences, Vol.16, No.4, pp. 123-124, 2011, DOI:10.3970/icces.2011.016.123

Abstract In this talk, we are going to introduce a new method that can detect the damage in bridge structures through the acceleration of a passing vehicle mounted with a tapping device. This method was inspired by the hunting behavior of woodpeckers and the idea of obtaining natural frequencies of bridge structures through the dynamic response of a passing vehicle [1].

Based on a simple vehicle-bridge interaction model, we analytically found out that the vehicle acceleration contains the damage information, which can be represented by the instantaneous stiffness Z as follows: (1)
where yB is the deflection of bridge,… More >