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Gongatti, Manoj Reddy Gongati (author)The two most common Post Consumer Recycled (PCR) plastics, isotactic polypropylene (iPP) and high density polyethylene (HDPE), differ in composition and mechanical behavior when compared to their virgin counterparts. This thesis focuses on understanding and modeling the mechanical performance of these two PCR plastics separately. Within this...master thesis 2022
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Lengkeek, H.J. (author)The Netherlands is inherently challenged by water, as a large part of the country lies below sea level and several major rivers in North-western Europe cross the country. The most prevalent form of protection from coastal and river floods in the Netherlands includes approximately 22,000 km of earthen dikes, of which 3800 km are primary flood...doctoral thesis 2022
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Thakolkaran, P. (author), Joshi, A. (author), Zheng, Y. (author), Flaschel, Moritz (author), De Lorenzis, Laura (author), Kumar, Siddhant (author)We propose a new approach for unsupervised learning of hyperelastic constitutive laws with physics-consistent deep neural networks. In contrast to supervised learning, which assumes the availability of stress–strain pairs, the approach only uses realistically measurable full-field displacement and global reaction force data, thus it lies...journal article 2022
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Golchin, A. (author), Vardon, P.J. (author), Hicks, M.A. (author)The formulation of a new thermo-mechanical constitutive model consistent with the principles of thermodynamics is presented. The model is capable of predicting the rate-independent thermo-mechanical behavior of fine-grained soils. The constitutive equations are derived by defining only a Gibbs-type free energy and a dissipation potential, in...journal article 2022
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Joshi, A. (author), Thakolkaran, P. (author), Zheng, Y. (author), Escande, Maxime (author), Flaschel, Moritz (author), De Lorenzis, Laura (author), Kumar, Siddhant (author)Within the scope of our recent approach for Efficient Unsupervised Constitutive Law Identification and Discovery (EUCLID), we propose an unsupervised Bayesian learning framework for discovery of parsimonious and interpretable constitutive laws with quantifiable uncertainties. As in deterministic EUCLID, we do not resort to stress data, but...journal article 2022
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Qian, Cheng (author), Gu, Tijian (author), Wang, Ping (author), Cai, Wei (author), Fan, Xuejun (author), Zhang, Kouchi (author), Fan, J. (author)Sintered nano-silver die-attach materials have been widely used in high-power electronics packaging because of their high thermal and electrical conductivities. In this study, we characterized the tensile properties of sintered nano-silver particles over a range of strain rates and temperatures, and established the constitutive models. First, 50...journal article 2022
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Xiao, Hong (author), Ling, Xing (author), Wang, Meng (author), Fang, Shu Wei (author), Wang, Haoyu (author)The bonding contact presents complex modes in polyurethane-mixed ballast. The commonly used parallel bond model is revised and four different contact models are developed including Ballast-Ballast Contact Bonding, Ballast-Ballast Noncontact Bonding, Ballast-Sleeper Contact Bonding, and Ballast-Sleeper Noncontact Bonding. The mechanical...journal article 2022
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Sousamli, M. (author), Messali, F. (author), Rots, J.G. (author)Plane-stress and shell macromodels are often preferred to analyze masonry structures because of their numerical efficiency. However, they often misestimate the hysteretic behavior of the structures. Additionally, due to the nature of smeared cracks, the cracks may be diffused. This article proposes a new orthotropic model, which focuses on...journal article 2022
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Kongshaug, Simen Sørgaard (author), Hendriks, M.A.N. (author), Kanstad, Terje (author), Markeset, Gro (author)Alkali–silica reaction (ASR) in concrete causes expansion and degradation of the material, which might give adverse structural consequences. From the structural engineer point view, the greatest concern is if ASR leads to loss of structural integrity. Two natural questions arise when assessing existing concrete structures affected by ASR: (1)...journal article 2022
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Fusco, Daniela (author), Messali, F. (author), Rots, J.G. (author), Addessi, Daniela (author), Pampanin, Stefano (author)Terraced houses built in the Netherland after 1980 are often characterized by the use of large units connected at corners by continuous thin layer mortar joints. Unlike the running bond pattern, usually modelled as a rigid connection, the vertical continuous connection may fail in shear and influence the global seismic capacity of the entire...journal article 2022
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Yan, R. (author), Xin, Haohui (author), Yang, Fei (author), El Bamby, H. (author), Veljkovic, M. (author), Mela, Kristo (author)The heat-affected zone (HAZ) is an unmelted region of a welded joint that has changed in material properties because of high temperatures during the welding process. HAZ has a lower strength than the base (parent) material (BM) and the weld metal (WM). The lower material strength is more significant if BM is made of high strength steel and...journal article 2022
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Zheng, Yiwen (author)Plasticity accompanied by dislocation motion is the essential property of metals. A large number of crystal plasticity models have been developed to predict the mechanical response in the work hardening regime while little attention is paid to pre-yield behavior. In this work, we propose a novel model both pre-yield and post-yield from a...master thesis 2021
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Zhang, Xinrui (author)Masonry is one of the most common building materials globally due to its ease of construction, price, durability and fire resistance. Its heterogeneity and orthotropic nature make its mechanical behaviour rather complex, highlighting the importance of an appropriate constitutive model to describe such behaviour accurately. In literature, most of...master thesis 2021
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Kashichenula, Keshav (author)Finite Element Analysis is an application used in many engineering fields, including geotechnical engineering. With increasing complexities of structures and material behavior, classical approach for non-linear finite element analysis has become computationally expensive (Gulikers, 2018). In order to improve the efficiency and accuracy of the...master thesis 2021
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Flaschel, Moritz (author), Kumar, Siddhant (author), De Lorenzis, Laura (author)We propose a new approach for data-driven automated discovery of isotropic hyperelastic constitutive laws. The approach is unsupervised, i.e., it requires no stress data but only displacement and global force data, which are realistically available through mechanical testing and digital image correlation techniques; it delivers interpretable...journal article 2021
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Jommi, C. (author), Chao, C. (author), Muraro, S. (author), Zhao, H.F. (author)Recent research effort carried out at Delft University of Technology to improve the experimental knowledge and develop a comprehensive modelling approach for fibrous organic soils is summarised. Experimental results and numerical analyses are combined to discuss some contradictory results which have delayed advanced characterisation of peats....journal article 2021
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Li, Lijun (author), Wang, Rui (author), Zhao, Hui (author), Zhang, Haoran (author), Yan, R. (author)This paper presents an experimental investigation on the dynamic mechanical performance of S30408 austenitic stainless steel (ASS) under elevated temperatures, which is essential for determining the behaviour of structures made with this type of steel subjected to the coupled fire and impact/explosion. For this purpose, the quasi-static and...journal article 2021
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Xie, Z. (author), Sousamli, M. (author), Messali, F. (author), Rots, J.G. (author)This paper proposes a sub-step based iterative constitutive model for line interface elements used to analyse masonry structures loaded in-plane. Based on a total deformation theory, the model adopts characteristics of multi-surface plasticity, including a Coulomb friction failure surface for shear, with tension and compression cut-off and...journal article 2021
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Mohsan, M. (author), Vardon, P.J. (author), Vossepoel, F.C. (author)A recursive ensemble Kalman filter (EnKF) is used as the data assimilation scheme to estimate strength and stiffness parameters simultaneously for a fully coupled hydro-mechanical slope stability analysis. Two different constitutive models are used in the hydro-mechanical model: the Mohr-Coulomb (MC) model and the Hardening Soil (HS) model....journal article 2021
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Liao, Kan (author)The suction pile foundation is a large steel cylinder with an open end and sealed top. This foundation type is widely used in the oil&gas industry and wind energy. Experimental investigation and numerical investigation are the main two methods to understand the performance of the suction bucket foundation. The experimental studies are...master thesis 2020