P. Vena¹, R. Contro

CMES-Computer Modeling in Engineering & Sciences, Vol.4, No.3&4, pp. 497-506, 2003, DOI:10.3970/cmes.2003.004.497

Abstract The adoption of artificial ligaments in current surgery is still characterised by a low success rate due to the fact that mechanical properties of the biomedical devices are such that a biomechanical compatibility is not fully satisfied. A durable artificial ligament should exhibit stiffness as well as strength properties which are such that a full articulation functionality is guaranteed. To this purpose, reliable numerical methods able to predict the mechanical behaviour of such devices both in the elastic and in inelastic range until complete rupture, could be used for designing of devices with tailored mechanical properties.

The present… More >

A. Frangi¹, L. Ghezzi, P. Faure-Ragani²

CMES-Computer Modeling in Engineering & Sciences, Vol.15, No.1, pp. 41-48, 2006, DOI:10.3970/cmes.2006.015.041

Abstract Three dimensional magneto-mechanical problems at low frequency are addressed by means of a coupled fast Boundary Element - Finite Element approach with total scalar potential and focusing especially on the issue of global force calculation on movable ferromagnetic parts. The differentiation of co-energy in this framework and the use of Maxwell tensor are critically discussed and the intrinsic links are put in evidence. Three examples of academic and industrial applications are employed for validation. More >

A. Sane^1,*, P. M. Padole¹, R. V. Uddanwadiker¹

CMES-Computer Modeling in Engineering & Sciences, Vol.115, No.2, pp. 281-294, 2018, DOI: 10.3970/cmes.2018.05046

Abstract T shaped skin-stiffener joint are one of the most commonly used structures in aerospace components. It has been proven in various studies that these joints are susceptible to failure when loaded in pull out conditions however, in specific applications these joints undergo pull loading. De-lamination/de-bond nucleation and its growth is one of the most common failure mechanisms in a fiber reinforced composite structure. Crack growth takes place due to the induced interlaminar normal and shear stresses between different structural constituents when a load is applied. In this study, Finite Element Analysis has been performed using cohesive contact interactions on a… More >

Qiang Tong¹, Qingwen Ren^{1, *}, Lei Shen ², Linfei Zhang ², Yin Yang³

CMES-Computer Modeling in Engineering & Sciences, Vol.114, No.1, pp. 33-58, 2018, DOI:10.3970/cmes.2018.114.033

Abstract In this article, the post-peak softening stage of the constitutive relation and the elastic stiffness degradation of concrete are investigated, and a highly reasonable constitutive relation curve is proposed. At the material level, the energy change in the concrete failure process is studied based on the different stress-strain curves of concrete under uniaxial tension and compression. The concrete failure criterion based on elastic strain energy density is deemed suitable and consistent with the experimental phenomena. The hysteresis phenomenon (lags behind the peak strength) is also discussed. At the structure level, the strength reduction method is employed for the stability analysis,… More >

Younho Cho, Weibin Li, Bin Yang

The International Conference on Computational & Experimental Engineering and Sciences, Vol.17, No.2, pp. 49-50, 2011, DOI:10.3970/icces.2011.017.049

Abstract This paper aims at an experimental method for detecting thermal-damages in a tube-like structure using acoustic nonlinear parameter of ultrasonic guided waves. The material nonlinearity of aluminum pipe specimens, which have been subjected to different heat-loading cycles, is measured to characterize the micro-damages. Flexible Polyvinylidene Fluoride (PVDF) comb transducers are used to generate and receive the fundamental and second harmonic waves. The amplitude of the second harmonic wave is extracted from the Fast Fourier Transform (FFT) spectrum of a received signal. The measured relative nonlinear parameter increases monotonically as a function of the propagation distance, and the relative nonlinear parameter… More >

Y.S. Chen, Y.H. Huang, B. Yeung, L. Liu, Y.Y. Hung

The International Conference on Computational & Experimental Engineering and Sciences, Vol.20, No.1, pp. 21-22, 2011, DOI:10.3970/icces.2011.020.021

Abstract Active thermography is an optical-based non-contact inspection method for full-field and quantitative measurement of surface radiation to predict potential faults or inner structure of a test object. The mechanism of the active thermography inspection is to excite the test object using appropriate thermal excitation methods and measure the corresponding thermal response. Active thermography conducts testing in a more controllable way and offer more reliable results compared to passive thermography. This paper reports the development of integrated systems featured some advanced excitation methods and thermal image processing methods. Experiments have been conducted on samples with disbonds, delaminations, internal cracks or voids,… More >

Peter Hess, Alexey M. Lomonosov, AndrAC Moura, Peter V. Grigoriev

The International Conference on Computational & Experimental Engineering and Sciences, Vol.20, No.1, pp. 3-4, 2011, DOI:10.3970/icces.2011.020.003

Abstract Crack generation by the steep shock fronts of laser-induced nonlinear surface acoustic wave (SAW) pulses and their nondestructive evaluation (NDE) by short linear SAW pulses was studied experimentally and theoretically. With the contactfree laser-based photoacoustic pump-probe technique, nondestructive testing could be extended to the characterization of elastic-shock-generated partially closed microcracks in the range of tens of micrometers.

By numerical simulations the propagation of thermoelastically launched broadband SAW pulses in nonlinear media and the initiation of crack growth is described. The characteristic features of SAW profiles in linear media, nonlinear media with quadratic nonlinearity, and nonlinear media with crack nucleation… More >

Takayuki Shiraiwa*, Fabien Briffod, Manabu Enoki

The International Conference on Computational & Experimental Engineering and Sciences, Vol.22, No.2, pp. 124-124, 2019, DOI:10.32604/icces.2019.05311

Abstract The purpose of this study is to evaluate fatigue performances of welded structures using numerical simulations. The fatigue life of welded joint is complicatedly affected by various factors such as geometries, defects, residual stress and microstructure. Conventional fatigue life assessments are generally based on fracture mechanics and predict the fatigue life for long crack propagation. In order to predict the total fatigue life more accurately, it is necessary to consider the lifetime for crack initiation and microstructually short crack (MSC) growth. In this study, a numerical framework to predict the fatigue life including crack initiation, MSC growth and long crack… More >

Brad Regez¹, Sridhar Krishnaswamy¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.12, No.4, pp. 111-112, 2009, DOI:10.3970/icces.2009.012.111

Abstract Ultrasonic inspection techniques have a proven record of applications during manufacturing and maintenance of metallic and composite aircraft structures. Traditional ultrasonic inspection techniques use a point-by-point scanning method to acquire a full-field image. This scanning method is slow and inadequate in satisfying modern manufacturing and maintenance time line requirements. The next generation of ultrasonic inspection eliminates the need for point-by-point scanning using an imaging array that is capable of displaying thousands of points to create a full-field image in real-time.
In this study, a next generation dual-channel ultrasonic imaging system is used for real-time three-dimensional evaluation of small composite aerospace… More >

Su Ji-Jun^1,2, Zhang Zhao-Cheng¹, Hu Hong¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.11, No.4, pp. 87-94, 2009, DOI:10.3970/icces.2009.011.087

Abstract This paper concentrates on the development and evaluation of linear characteristics of a complex flexure hinge with high accuracy and large stiffness. The flexure hinge mechanism is used to clamp the shaft of a micropositioning stage based on the inchworm principle. Six key parameters of the flexure hinge are optimized by using finite element method. Developed flexure hinge has very good effects on the clamping and resilience that are accurate and reasonable. The evaluation result shows that the flexure hinge has excellent linear characteristic. More >