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 More >

Saptarshi Sasmal¹, K. Ramanjaneyulu²

Structural Durability & Health Monitoring, Vol.7, No.4, pp. 253-282, 2011, DOI:10.3970/sdhm.2011.007.253

Abstract This paper proposes a methodology for damage detection in beam like structures using vibration characteristics obtained from transfer matrix technique. At first, vibration characteristics of beam-like structure have been determined with the help of a computer program developed based on the formulations presented in this paper. Then, a detailed study has been carried out to categorise the influence of damage on frequency and mode shape (both displacement and rotational) information. For a structure with known magnitude and location of damage(s), frequencies and mode shape information are obtained and the same has been used in determining… More >

K. Wang, S.J. Zhou, Z.F. Nie

The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.4, pp. 115-116, 2011, DOI:10.3970/icces.2011.018.115

Abstract The natural neighbour Galerkin method is tailored to solve boundary value problems of the couple-stress elasticity to model the size dependent behaviour of materials. This method is based on the displacement-based Galerkin approach, and the calculation of the global stiffness matrix is performed using gradient smoothing technique combined with the non-Sibsonian partition of unity approximation scheme. This method possesses the following properties: the complex C1-continuous approximation scheme is avoided without using either Lagrange multipliers or penalty parameters; no domain integrals involved in the assembly of the global stiffness matrix; and the imposition of essential boundary More >

Zhanwei Liu, Huimin Xie, Fulong Dai

The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.3, pp. 95-96, 2011, DOI:10.3970/icces.2011.018.095

Abstract The mechanical behaviors of microstructures and micro devices have drawn the attention from researchers on materials and mechanics recently. To understand the rule of these behaviors, the deformation measurement techniques with micro/nanometer sensitivity and spatial resolution are required. In this report, a geometric phase analysis technique, SEM scanning moirAC method, digital phase moirAC method based on gratings and a micro-marker identification method are introduced to meet the deformation evaluation requirement of MEMS. The geometric phase analysis technique is performed on the basis of regular gratings, instead of natural atom lattice. The regular gratings with a… More >

Guo Baoqiao, Chen Pengwan, Zhang Qingming, Li Yanjie, Xie Huimin

The International Conference on Computational & Experimental Engineering and Sciences, Vol.17, No.4, pp. 115-116, 2011, DOI:10.3970/icces.2011.017.115

Abstract Optical full-field measurement methods are now widely applied in various domains. In general, the displacement fields can be directly obtained from the measurement; however in mechanical analysis strain fields are preferred. To extract strain fields from noisy displacement fields is always a challenging topic. In this study, a finite element method for smoothing displacement fields and calculating strain fields is proposed. An experimental test case on a holed aluminum specimen under tension is applied to validate this method. The heterogeneous displacement fields of the area around the hole are measured by the digital image correlation More >

Ke JI, nlong Chen, Lina Zhang, Xinhua Ji

The International Conference on Computational & Experimental Engineering and Sciences, Vol.17, No.2, pp. 35-36, 2011, DOI:10.3970/icces.2011.017.035

Abstract The Stress distribution of contact area in engineering structure is complex. Automatic whole-field measurement of photo-elasticity is a feasibility method to solve the contact problem. However, the problem of isoclinic and isochromatic interaction is important in phase-shifting techniques in photo-elasticity. The technique named 8-step phase shifting technique is applied to solve the problem of isoclinic fringe pattern influenced by isochromatic fringe patterns in integer order and half-integer order. Isoclinic parameter in the range of [0,I/2] is given by the method.

Based on the eight-step phase shifting technique, some methods to determine the first principal stress… More >

Xianfu Huang, Zhanwei Liu, Jianxin Gao, Huimin Xie

The International Conference on Computational & Experimental Engineering and Sciences, Vol.17, No.1, pp. 25-26, 2011, DOI:10.3970/icces.2011.017.025

Abstract The spatial laser interferometry with combination of fast Fourier transformation (FFT) technique has been applied to analyze and reshape 3D profile of micro objects in this paper. In this technique, two beam of coherent spatial laser would superpose and interfere with each other to produce fringes with constant pitches. Deformed fringe lines would be generated on a tested object surface for its 3D height existence when a micro-movable platform with the tested object on it is placed in the spatial interferential fringe field. On the analysis of the fringe pattern collected by CCD which carries… More >

Peng Wang

The International Conference on Computational & Experimental Engineering and Sciences, Vol.20, No.4, pp. 117-118, 2011, DOI:10.3970/icces.2011.020.117

Abstract Current trends in high performance computing (HPC) are moving towards the availability of several cores on the same chip of contemporary processors in order to achieve speed-up through the extraction of potential fine-grain parallelism of applications. The trend is led by GPUs, which have been developed exclusively for computational tasks as massively-parallel co-processors to the CPU. During 2010 an extensive set of new HPC architectural feature were developed in the third generation of NVIDIA GPUs (Fermi), giving computational mechanics an opportunity to expand use of GPU modelling and simulation.

This presentation will examine examples relevant More >

Linggang Kong, Yunmin Chen, Yanguo Zhou, Jianqun Jiang

The International Conference on Computational & Experimental Engineering and Sciences, Vol.20, No.4, pp. 107-108, 2011, DOI:10.3970/icces.2011.020.107

Abstract To investigate geotechnical systems, high gravity is needed due to the dominance of material self-weight. A centrifuge is a common technique to generate high gravity, which causes centrifugal acceleration. In geotechnical physical modeling, geotechnical centrifuge can generate the same gravity stress as the prototype, guarantees the consistency of model deformation and failure mechanism between the centrifugal model and real objects and solve complex problems in geotechnical engineering, hydraulic engineering and environmental engineering etc. In view of the scientific values of centrifuge and shaking table, Zhejiang University develops one of the largest geotechnical centrifuges in China.… More >

Chi-Ming Lee, NASA Glenn Research Center

The International Conference on Computational & Experimental Engineering and Sciences, Vol.20, No.3, pp. 75-76, 2011, DOI:10.3970/icces.2011.020.075

Abstract The fuel-flexible, low-NOx (Nitrogen oxides) combustor task of the Environmentally Resonsible Aviation (ERA) project is to develop a low emissions combustor capable of meeting the Landing and Take-Off (LTO) NOx emissions reduction while reducing aircraft fuel burn by 50% without negatively impacting other emissions and achieving perceived noise levels 42 dB below stage 4 limits. The low emissions combustor should be capable of meeting the mid-term LTO NOx goal of 75% reduction from the International Civil Aviation Organization (ICAO) standard adopted at Committee on Aviation Environment Protection (CAEP 6). In addition to NOx and Other… More >