A. Kroworz¹, A. Katunin^1,*

Structural Durability & Health Monitoring, Vol.12, No.1, pp. 1-18, 2018, DOI:10.3970/sdhm.2018.012.001

Abstract Non-destructive testing (NDT) of structures is one of the most important tasks of the proper maintenance and diagnosis of machines and constructions structural condition. NDT methods contribute to the damage tolerance philosophy used in the aircraft design methodology as well as many other operation and maintenance programs of machinery and constructions. The following study is focusing on overviewing an important group of NDT methods: the optical and other ones, which found broad applicability in scientific and industrial studies nowadays. The paper discusses the selected most widely applicable methods, namely, visual testing, ultrasonic testing, radiographic testing, infrared thermography as well as… More >

Lilan Gao^1,2,*, Qingxian Yuan^1,2, Ruixin Li^3,*, Lei Chen^1,2, Chunqiu Zhang^1,2, Xizheng Zhang^1,2

Molecular & Cellular Biomechanics, Vol.15, No.2, pp. 85-98, 2018, DOI: 10.3970/mcb.2018.00329

Abstract Silk fibroin-typeⅡcollagen scaffold was made by 3D printing technique and freeze-drying method, and its mechanical properties were studied by experiments and theoretical prediction. The results show that the three-dimensional silk fibroin-typeⅡ collagen scaffold has good porosity and water absorption, which is (89.3%+3.26%) and (824.09%+93.05%), respectively. With the given strain value, the stress of scaffold decreases rapidly firstly and then tends to be stable during the stress relaxation. Both initial and instantaneous stresses increase with increase of applied strain value. The creep strains of scaffold with different stress levels show the two stages: the rapidly increasing stage and the second stable… More >

O. Allix¹, P. Gosselet¹, P. Kerfriden², K. Saavedra³

CMC-Computers, Materials & Continua, Vol.32, No.2, pp. 107-132, 2012, DOI:10.3970/cmc.2012.032.107

Abstract This paper deals with the parallel simulation of delamination problems at the meso-scale by means of multi-scale methods, the aim being the Virtual Delamination Testing of Composite parts. In the non-linear context, Domain Decomposition Methods are mainly used as a solver for the tangent problem to be solved at each iteration of a Newton-Raphson algorithm. In case of strongly non linear and heterogeneous problems, this procedure may lead to severe difficulties. The paper focuses on methods to circumvent these problems, which can now be expressed using a relatively general framework, even though the different ingredients of the strategy have emerged… More >

Alireza Sarebanha^1,*, Andreas H. Schellenberg², Matthew J. Schoettler³, Gilberto Mosqueda⁴, Stephen A. Mahin^†

CMES-Computer Modeling in Engineering & Sciences, Vol.120, No.3, pp. 693-717, 2019, DOI:10.32604/cmes.2019.04846

Abstract Hybrid simulation can be a cost effective approach for dynamic testing of structural components at full scale while capturing the system level response through interactions with a numerical model. The dynamic response of a seismically isolated structure depends on the combined characteristics of the ground motion, bearings, and superstructure. Therefore, dynamic full-scale system level tests of isolated structures under realistic dynamic loading conditions are desirable towards a holistic validation of this earthquake protection strategy. Moreover, bearing properties and their ultimate behavior have been shown to be highly dependent on rate-of-loading and scale size effects, especially under extreme loading conditions. Few… More >

Tianliang Qin¹, Libin Zhao^2,3,*, Jifeng Xu¹, Fengrui Liu^2,3,4, Jianyu Zhang⁵

CMES-Computer Modeling in Engineering & Sciences, Vol.118, No.1, pp. 157-176, 2019, DOI:10.31614/cmes.2019.04379

Abstract Progressive damage models (PDMs) have been increasingly used to simulate the failure process of composite material structures. To accurately simulate the damage in each ply, 3D PDMs of composite materials have received more attention recently. A characteristic element length (CEL), which is an important dimensional parameter of PDMs for composite materials, is quite difficult to obtain for 3D elements, especially considering the crack directions during damage propagation. In this paper, CEL models for 3D elements in PDMs of unidirectional composite structures are presented, and their approximate formulae are deduced. The damage in unidirectional composite materials can be divided into fiber… More >

Xiaoxia Yang¹, Shili Chen¹, Fang Sun¹, Shijiu Jin¹, Wenshuang Chang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.90, No.6, pp. 487-500, 2013, DOI:10.3970/cmes.2013.090.487

Abstract Ultrasonic phased array inspection technology is widely used in nondestructive evaluation (NDE) applications and it has been proved to be an effective method for flaw detections in industry. In our study, this nondestructive evaluation method is proposed to detect the corrosion defects on engine cylinders. In order to demonstrate its feasibility, it is necessary to study the characteristics of the acoustic field produced by a linear phased array ultrasonic transducer in the engine cylinders. In this paper, according to multi-Gaussian beam model and ray acoustics theory, we derive the expression of the acoustic field from a linear phased array ultrasonic… More >

D.P. Boso¹, M. Lefik²

CMES-Computer Modeling in Engineering & Sciences, Vol.55, No.3, pp. 319-338, 2010, DOI:10.3970/cmes.2010.055.319

Abstract In this paper we study numerically the mechanical behaviour of wire ropes, particularly the influence of the geometrical configuration on the overall stiffness of the cables. Modelling the behaviour of a cable is a difficult problem, given the complexity of the geometrical layout, contact phenomena occurring among wires and possible yielding of the material. For this reason we pursue a "hierarchical beam approach", to substitute recursively, at each cabling stage, the bundle of wires with an equivalent single strand, having the characteristics computed from the previous level. We consider the first two levels of the bundle hierarchy and investigate the… More >

L. Gornet¹, S. Marguet², G. Marckmann³

CMC-Computers, Materials & Continua, Vol.4, No.2, pp. 63-74, 2006, DOI:10.3970/cmc.2006.004.063

Abstract The purpose of the present study is to determine the components of the effective elasticity tensor and the failure properties of Nomex^® honeycomb cores. In order to carry out this study, the NidaCore software, a program dedicated to Nomex®Cores predictions, has been developed using the Finite Element tool Cast3M-CEA. This software is based on periodic homogenization techniques and on the modelling of structural instability phenomena. The homogenization of the periodic microstructure is realized thanks to a strain energy approach. It assumes the mechanical equivalence between the microstructures of a RVE and a similar homogeneous macroscopic volume. The key point of… More >

Ou Zhang^1,*, Xueye Wei¹

CMC-Computers, Materials & Continua, Vol.58, No.2, pp. 529-544, 2019, DOI:10.32604/cmc.2019.04075

Abstract Aiming at the detection of the sucker rod defects, a real-time detection system is designed using the non-destructive testing technology of magnetic flux leakage (MFL). An MFL measurement system consists of many parts, and this study focuses on the signal acquisition and processing system. First of all, this paper introduces the hardware part of the acquisition system in detail, including the selection of the Hall-effect sensor, the design of the signal conditioning circuit, and the working process of the single chip computer (SCM) control serial port. Based on LabVIEW, a graphical programming software, the software part of the acquisition system… More >

P. PattunnaRajam^{1, *}, Reeba korah², G. Maria Kalavathy³

CMC-Computers, Materials & Continua, Vol.54, No.3, pp. 251-268, 2018, DOI:10.3970/cmc.2018.054.251

Abstract This paper presents an automated POCOFAN-POFRAME algorithm that partitions large combinational digital VLSI circuits for pseudo exhaustive testing. In this paper, a simulation framework and partitioning technique are presented to guide VLSI circuits to work under with fewer test vectors in order to reduce testing time and to develop VLSI circuit designs. This framework utilizes two methods of partitioning Primary Output Cone Fanout Partitioning (POCOFAN) and POFRAME partitioning to determine number of test vectors in the circuit. The key role of partitioning is to identify reconvergent fanout branch pairs and the optimal value of primary input node N and fanout… More >