document

Numerical investigation of the equipment set-up in triaxial testing of soft soils

Chao, C. (author), Jommi, C. (author), Muraro, S. (author)

Element testing of soft soils is challenging due to the large strains attained in the pre-failure range. Besides the heterogeneity of natural samples, the set-up configuration is the main driving factor for non-homogenous response. Stress, strain and pore pressure non-uniformities induced by the loading system affect the observed behaviour and...

conference paper 2023

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Buckling assessment of GFRP and carbon fiber-reinforced plastic filament-wound tubes using an acoustic emission-based methodology

Alimirzaei, Sajad (author), Ahmadi Najafabadi, Mehdi (author), Bani Mohammad Ali, Amir (author), Pahlavan, Lotfollah (author)

The aim of this research is to investigate the failure mechanisms of the filament-wound composite tubes under axial compressional loading by using an acoustic emission approach. First, the mechanical properties of ±45°C composite tubes were obtained experimentally. Then, failure due to the buckling phenomenon and crashworthiness...

journal article 2023

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Investigation of energy absorption capacity of 3D filament wound composite tubes: experimental evaluation, numerical simulation, and acoustic emission monitoring

Alimirzaei, Sajad (author), Ahmadi Najafabadi, Mehdi (author), Nikbakht, Ali (author), Pahlavan, Lotfollah (author)

By analyzing the failure mechanisms, crashworthiness characteristics of FW composite tubes subjected to two modes of progressive damage and catastrophic failure are investigated using acoustic emission technique and numerical method. The AE signals of ±45° composite tubes were classified using hierarchical and wavelet transform methods, and...

journal article 2023

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Numerical modelling of rolling contact fatigue damage initiation from non-metallic inclusions in bearing steel

Ravi, Gopalakrishnan (author), De Waele, Wim (author), Nikolic, Ksenija (author), Petrov, R.H. (author), Hertelé, Stijn (author)

Bearing failure is a cause of concern in a variety of machinery such as turbines, transmissions, drills, engines, etc. It is often associated with rolling contact fatigue (RCF) triggered from damage initiation at non-metallic inclusions (NMI's). Experimental evidence shows that damage initiation lifetime is highly sensitive to the NMI...

journal article 2023

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Damage mechanism characterization of ±35° and ±55° FW composite tubes using acoustic emission method

Alimirzaei, Sajad (author), Najafabadi, Mehdi Ahmadi (author), Nikbakht, Ali (author), Pahlavan, Lotfollah (author)

The focus of this study is to investigate the mechanical properties, of ±35° and ±55° filament wound (FW) composite tubes under axial compression loading using the acoustic emission technique. For this purpose, material failure, crashworthiness characteristics, and the effect of each mechanism on the energy absorption capacity were studied...

journal article 2022

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Finite Element Analysis of Power Module Packages with One-step Molding for Power Inductors

Li, Xiao (author), Tang, Jiuyang (author), Zhao, Jiayan (author), Li, Jinbing (author), Zhang, Kouchi (author), Liu, Pan (author)

With the development of 5G communication technology and the rise of power semiconductors, the switching frequency of the circuit keeps increasing, which pushes for miniaturization of power modules and related components. Therefore, in this paper, a one-step molding technology was proposed for a DC/DC buck converter power module. We proposed a...

conference paper 2022

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Thermal FEM Analysis of Surge Arresters during HVDC Current Interruption Validated by Experiments

Liu, S. (author), Popov, M. (author), Belda, Nadew (author), Smeets, Rene (author), Liu, Zhiyuan (author)

This paper deals with the development of an accurate finite-element model of an arrester to investigate the electrothermal and mechanical stress during dc current interruption. The comprehensive analysis performed on a ZnO surge arrester is supported by experiments during high-voltage dc circuit breaker current interruption. The performed...

journal article 2022

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Mesh size effects on fracture locus of high strength bolts: A mesoscale critical equivalent plastic strain (MCEPS) approach

Li, Jie (author), Xin, Haohui (author), Correia, J.H.G. (author), Berto, Filippo (author), Zhao, Bingzhen (author), Bo, Yanwei (author), Veljkovic, M. (author)

With the improvement of computational capability, finite element simulation is an increasingly practical method to accurately predict the ultimate capacity and ductile fracture behavior of high-strength bolts. However, the mesh size affects the results of FE simulations but related research on mesh size effects is relatively limited. In the...

journal article 2022

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EMC oxidation under high temperature aging

Inamdar, A.S. (author), Gromala, Przemyslaw Jakub (author), Prisacaru, Alexandru (author), Kabakchiev, Alexander (author), Yang, Yu Hsiang (author), Han, Bongtae (author)

Epoxy molding compound (EMC) is widely used for encapsulating automotive electronics. Among all of the components of an electronic package, EMC is most exposed to the atmosphere, and thus undergoes aging. During high-temperature operation, EMC is oxidized, which alters its mechanical properties, and thus can affect the reliability of electronic...

book chapter 2022

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Multi-Physics Driven Electromigration Study: Multi-Scale Modeling and Experiment

Cui, Z. (author)

This dissertation presents a comprehensive and integrated study, including theory development, numerical simulation and experiment, for multi-physics driven electromigration in microelectronics. Multi-scale methodologies from atomistic modeling to continuum theory-based simulation have been developed. Moreover, extensive experimental testing,...

doctoral thesis 2021

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Experiments and numerical simulation of wire and arc additive manufactured steel materials

Xin, H. (author), Tarus, I.A. (author), Cheng, L. (author), Veljkovic, M. (author), Persem, Nicolas (author), Lorich, Laurent (author)

In recent years, wire arc additive manufacturing (WAAM) has increasingly attracted attention in the construction sector because of its ability to optimize the production of large metallic structural parts, and for use in connections suitable for easy execution and potential reuse. The technology has become mature leading to shorter fabrication...

journal article 2021

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Simulation of deformation and fracture initiation during equal channel angular pressing of AZ31 magnesium alloy with covered tube casing

Eivani, A.R. (author), Mirghasemi, S. M. (author), Seyedein, S. H. (author), Zhou, J. (author), Jafarian, H. R. (author)

The present research was aimed at lowering the deformation temperature by applying cover tube casing (CTC) to AZ31 magnesium alloy samples subjected to equal channel angular pressing (ECAP) without triggering surface defects and/or fracture. The Cockcroft-Latham (C & L) fracture model was incorporated into finite element simulation and...

journal article 2021

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Mechanical behavior of metallic strip flexible pipes during reeling operation

Xu, Yuxin (author), Fang, P. (author), Bai, Yong (author)

Metallic strip flexible pipes (MSFP), a relatively new style of unbonded flexible pipes, are considered as an attractive alternative to traditional submarine pipes. During its reeling operation, it will inevitably confront various complicated loads, which may affect the integrity and safety of MSFP's utilization. In this paper, the tension...

journal article 2021

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Fracture parameters calibration and validation for the high strength steel based on the mesoscale failure index

Xin, Haohui (author), Correia, José A.F.O. (author), Veljkovic, M. (author), Berto, Filippo (author)

Accurately obtaining the material parameters of the damage model is very important for the ductile fracture simulation of steel structures made of high strength steel (HSS). The combination of micromechanics with the uncoupled phenomenological fracture model can be used to obtain the material parameters of ductile fracture locus only from the...

journal article 2021

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Ductile fracture locus identification using mesoscale critical equivalent plastic strain

Xin, Haohui (author), Veljkovic, M. (author), Correia, José A.F.O. (author), Berto, Filippo (author)

The ductile performance of high strength steel (HSS) from different steel grades, producers, manufacturing processes varies a lot. It is also difficult to conduct all kinds of reliable experiments to generate different stress status through different initial specimen geometries or by applying different load combinations in the civil...

journal article 2021

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Computational homogenization simulation on steel reinforced resin used in the injected bolted connections

Xin, H. (author), Nijgh, M.P. (author), Veljkovic, M. (author)

In this paper, compressive material tests on unconfined/confined resin and steel reinforced resin were experimentally evaluated in order to validate the numerical results. The uniaxial model which combines damage mechanics and Ramberg-Osgood relationship is proposed in this paper to describe the uniaxial compressive behaviour of resin and...

journal article 2019

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Mechanical properties of (steel-reinforced) resins used in injected bolted connections

Nijgh, M.P. (author), Xin, H. (author), Veljkovic, M. (author)

This paper illustrates the most recent developments in the field of injected bolted connections. A novel injection material, steel-reinforced resin, is used to enhance stiffness of resin-injected bolted shear connections. The main goal is to achieve the slip resistance connection in a clearance holes without pre-tensioning of bolts. Steel...

conference paper 2019

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Pre-cracking development of weld-induced squats due to plastic deformation: Five-year field monitoring and numerical analysis

Deng, X. (author), Li, Z. (author), Qian, Zhiwei (author), Zhai, Wanming (author), Xiao, Qian (author), Dollevoet, R.P.B.J. (author)

Weld-induced squats are a major damage type in high-speed railways as well as in conventional railways. They incur high maintenance costs and endanger operational safety. This paper first presents and analyzes five-year continual field monitoring observations and measurements of squats at rail welds. A hypothesis of the formation and development...

journal article 2019

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Method for evaluating the performance of railway crossing rails after long-term service

Wei, Z. (author), Nunez, Alfredo (author), Boogaard, M.A. (author), Dollevoet, R.P.B.J. (author), Li, Z. (author)

In this paper, we present a method for evaluating the performance of railway crossing rails after long-term service. The method includes 1) 3D profile and hardness measurements; 2) finite element simulation of wheel/rail interaction; and 3) numerical prediction of rail degradation. We conducted a case study on a crossing that had been in service...

journal article 2018

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Crack pattern observations to finite element simulation: An exploratory study for detailed assessment of reinforced concrete structures

Dhanmeher, Saurabh (author)

Uncertainties regarding structural safety of reinforced concrete structures may warrant a need for a detailed assessment. A detailed assessment using nonlinear finite element analysis is one of the alternatives which could help in decision-making about maintaining, upgrading or even demolishing and rebuilding of the structure. A reliable...

master thesis 2017