- document
-
Mirkhalaf, Mohsen (author), Rocha, I.B.C.M. (author)During the last few decades, industries such as aerospace and wind energy (among others) have been remarkably influenced by the introduction of high-performance composites. One challenge, however, for modeling and designing composites is the lack of computational efficiency of accurate high-fidelity models. For design purposes, using...journal article 2024
- document
-
Storm, J. (author), Rocha, I.B.C.M. (author), van der Meer, F.P. (author)Simulating the mechanical response of advanced materials can be done more accurately using concurrent multiscale models than with single-scale simulations. However, the computational costs stand in the way of the practical application of this approach. The costs originate from microscale Finite Element (FE) models that must be solved at every...journal article 2024
- document
-
Rocha, I.B.C.M. (author), Kerfriden, P. (author), van der Meer, F.P. (author)In this work we present a hybrid physics-based and data-driven learning approach to construct surrogate models for concurrent multiscale simulations of complex material behavior. We start from robust but inflexible physics-based constitutive models and increase their expressivity by allowing a subset of their material parameters to change in...journal article 2023
- document
-
Alves Maia, M. (author), Rocha, I.B.C.M. (author), Kerfriden, P. (author), van der Meer, F.P. (author)Driven by the need to accelerate numerical simulations, the use of machine learning techniques is rapidly growing in the field of computational solid mechanics. Their application is especially advantageous in concurrent multiscale finite element analysis (FE<sup>2</sup>) due to the exceedingly high computational costs often associated with it...journal article 2023
- document
-
Rocha, Isabelly (author), Felber, Pascal (author), Schiavoni, Valerio (author), Chen, Lydia Y. (author)Deep Neural Networks (DNNs) have demonstrated impressive performance on many machine-learning tasks such as image recognition and language modeling, and are becoming prevalent even on mobile platforms. Despite so, designing neural architectures still remains a manual, time-consuming process that requires profound domain knowledge. Recently,...conference paper 2022
- document
-
Alves Maia, M. (author), Rocha, I.B.C.M. (author), van der Meer, F.P. (author)In a concurrent (FE2) multiscale modeling is an increasingly popular approach for modeling complex materials. As such, it is especially suited for modeling composites, as their complex microstructure can be explicitly modeled and nested to each integration point of the macroscale. However, this generality is often associated with exceedingly...conference paper 2022
- document
-
Gouicem, Redha (author), Sprokholt, D.G. (author), Ruehl, Jasper (author), Rocha, Rodrigo C.O. (author), Spink, Tom (author), Chakraborty, S.S. (author), Bhatotia, Pramod (author)Dynamic Binary Translation (DBT) is a powerful approach to support cross-architecture emulation of unmodified binaries. However, DBT systems face correctness and performance challenges, when emulating concurrent binaries from strong to weak memory consistency architectures. As a matter of fact, we report several translation errors in QEMU,...conference paper 2022
- document
-
Starkova, Olesja (author), Gagani, Abedin I. (author), Karl, Christian W. (author), Rocha, I.B.C.M. (author), Burlakovs, Juris (author), Krauklis, Andrey E. (author)Polymers and polymer composites are negatively impacted by environmental ageing, reducing their service lifetimes. The uncertainty of the material interaction with the environment compromises their superior strength and stiffness. Validation of new composite materials and structures often involves lengthy and expensive testing programs....journal article 2022
- document
-
Krauklis, Andrey E. (author), Karl, Christian W. (author), Rocha, I.B.C.M. (author), Burlakovs, Juris (author), Ozola-Davidane, Ruta (author), Gagani, Abedin I. (author), Starkova, Olesja (author)Service lifetimes of polymers and polymer composites are impacted by environmental ageing. The validation of new composites and their environmental durability involves costly testing programs, thus calling for more affordable and safe alternatives, and modelling is seen as such an alternative. The state-of-the-art models are systematized in...review 2022
- document
-
Barroso, Elias Saraiva (author), Ribeiro, Leonardo Gonçalves (author), Alves Maia, M. (author), Rocha, I.B.C.M. (author), Parente, Evandro (author), de Melo, Antônio Macário Cartaxo (author)This paper presents BIOS (acronym for Biologically Inspired Optimization System), an object-oriented framework written in C++, aimed at heuristic optimization with a focus on Surrogate-Based Optimization (SBO) and structural problems. The use of SBO to deal with structural optimization has grown considerably in recent years due to the...journal article 2022
- document
-
Rocha, Rodrigo C.O. (author), Sprokholt, D.G. (author), Fink, Martin (author), Gouicem, Redha (author), Spink, Tom (author), Chakraborty, S.S. (author), Bhatotia, Pramod (author)The emergence of new architectures create a recurring challenge to ensure that existing programs still work on them. Manually porting legacy code is often impractical. Static binary translation (SBT) is a process where a program's binary is automatically translated from one architecture to another, while preserving their original semantics....conference paper 2022
- document
-
Tambara Jr, L.U.D. (author), Rocha, J.C. (author), Cheriaf, M. (author), Palomo, A. (author), Fernández-Jiménez, A. (author)The effect of including 5 % chloride salts (NaCl and CaCl2) on calcium sulfoaluminate cement hydration was studied. The rate of heat release, setting times and mechanical strength were determined in 2 d, 28 d and 90 d cement pastes. The hydration products formed at those ages were identified with XRD and SEM. Hydration reactions were hastened...conference paper 2021
- document
-
Frasson, Bruna J. (author), Rocha, Janaíde C. (author)Release of silicon and alumina from aluminosilicate occurs at early stages of alkaline reaction. Alkalinity and different aluminosilicate could influence dissolution of particles and modify microstructure of alkali-activated systems. However, there is a lack of study regarding the effects of Portland cement (OPC) addition on alkali-activated...conference paper 2021
- document
-
Rocha, I.B.C.M. (author), Kerfriden, P. (author), van der Meer, F.P. (author)Concurrent multiscale finite element analysis (FE<sup>2</sup>) is a powerful approach for high-fidelity modeling of materials for which a suitable macroscopic constitutive model is not available. However, the extreme computational effort associated with computing a nested micromodel at every macroscopic integration point makes FE<sup>2</sup>...journal article 2021
- document
-
Carvalho, Rui F.S. (author), Pereira, Giovannia A.L. (author), Rocha, João (author), Castro, M. Margarida C.A. (author), Granadeiro, Carlos M. (author), Nogueira, Helena I.S. (author), Peters, J.A. (author), Geraldes, Carlos F.G.C. (author)The NMR relaxivities of the decatungstolanthanoate core-shell nanoparticles, prepared by encapsulating [Ln(W<sub>5</sub>O<sub>18</sub>)<sub>2</sub>]<sup>9−</sup> polyoxometalates (LnPOM) within amorphous silica shells (K<sub>9</sub>[Ln(W<sub>5</sub>O<sub>18</sub>)<sub>2</sub>]@SiO<sub>2</sub>), were studied along the Ln series. The relaxivity...journal article 2021
- document
-
Rocha, I.B.C.M. (author), van der Meer, F.P. (author), Sluys, Lambertus J. (author)This work presents a reduced-order modeling framework that precludes the need for offline training and adaptively adjusts its lower-order solution space as the analysis progresses. The analysis starts with a fully-solved step and elements are clustered based on their strain response. Elements with the highest strains are solved with a local...journal article 2020
- document
-
Rocha, I.B.C.M. (author), Kerfriden, P. (author), van der Meer, F.P. (author)Although being a popular approach for the modeling of laminated composites, mesoscale constitutive models often struggle to represent material response for arbitrary load cases. A better alternative in terms of accuracy is to use the FE<sup>2</sup> technique to upscale microscopic material behavior without loss of generality, but the...journal article 2020
- document
-
Rocha, I.B.C.M. (author)Although being a crucial step in structural design of laminated composites, prediction of their long-term mechanical performance remains a challenging task for which no comprehensive and reliable solution is currently available. Nevertheless, structures such as wind turbine blades, of which laminated composites constitute the main load bearing...doctoral thesis 2019
- document
-
A combined experimental/numerical investigation on hygrothermal aging of fiber-reinforced compositesRocha, I.B.C.M. (author), van der Meer, F.P. (author), Raijmaekers, S. (author), Lahuerta, F. (author), Nijssen, R. P.L. (author), Mikkelsen, L. P. (author), Sluys, Lambertus J. (author)This work investigates hygrothermal aging degradation of unidirectional glass/epoxy composite specimens through a combination of experiments and numerical modeling. Aging is performed through immersion in demineralized water. Interlaminar shear testes are performed after multiple conditioning times and after single immersion/redrying cycles....journal article 2019
- document
-
Tisaire, Jordi Escuder (author), Rodrigo, Elena Martín (author), Ribeiro, Sofia (author), Ricci, Mariachiara (author), Cuellar Lopez, J.S. (author), Zeugolis, Dimitrios (author), Bayon, Yves (author), Rocha, Isabel (author)Lymphedema is a chronic and progressive condition derived from impaired lymphatic system function. Lymphedema is incurable, progressive, disfiguring, disabling and has adverse psychosocial effects. Upper extremity lymphedema is mainly the consequence of breast cancer surgery. Several methods to diagnose lymphedema exist; however, these...conference paper 2019