The Experts below are selected from a list of 326448 Experts worldwide ranked by ideXlab platform
Thomas Siegmund - One of the best experts on this subject based on the ideXlab platform.
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a numerical study of transient fatigue crack growth by use of an irreversible cohesive zone Model
International Journal of Fatigue, 2004Co-Authors: Thomas SiegmundAbstract:Abstract Transient fatigue crack growth is studied for a material system in which the crack tip is shielded due to crack bridging. The process of material separation during fatigue crack growth is described by the use of an irreversible cohesive zone Model. In contrast to past developments of cohesive zone Models, the traction–separation behavior does not follow a predefined path, but is dependent on the evolution of the damage dependent cohesive zone properties. The Model Definition is given and the basic uniaxial response of the Model documented. The cohesive zone Model is subsequently applied in a numerical study of transient fatigue crack growth. Single overload cases are computed to demonstrate the effects of variations in the cohesive zone properties. Block loading sequences with variations in the amplitude and the load ratio are computed. Model predictions qualitatively compare well to experimentally observed effects of fatigue crack growth transients in materials with crack bridging zones.
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an irreversible cohesive zone Model for interface fatigue crack growth simulation
Engineering Fracture Mechanics, 2003Co-Authors: Thomas SiegmundAbstract:Abstract Fatigue crack growth (FCG) along an interface is studied. Instead of using the Paris equation, the actual process of material separation during FCG is described by the use of an irreversible constitutive equation for the cyclic interface traction–separation behavior within the cohesive zone Model (CZM) approach. In contrast to past development of CZMs, the traction–separation behavior does not follows a predefined path. The Model Definition, its predicted cyclic material separation behavior and application to a numerical study of interface FCG in double-cantilever beam, end-loaded split and mixed-mode beam specimens are reported.
Thierry Nalpas - One of the best experts on this subject based on the ideXlab platform.
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GravPSO2D: A Matlab package for 2D gravity inversion in sedimentary basins using the Particle Swarm Optimization algorithm
Computers & Geosciences, 2021Co-Authors: J.l.g. Pallero, J.l. Fernández-martínez, Z. Fernández-muñiz, Sylvain Bonvalot, Germinal Gabalda, Thierry NalpasAbstract:In this paper GravPSO2D, a Matlab tool for two-dimensional gravity inversion in sedimentary basins using the Particle Swarm Optimization (PSO) algorithm, is presented. The package consists of a collection of functions and scripts that cover the main three parts of the process: (1) the Model Definition based on the observations, (2) the inversion itself, where the PSO is employed, and (3) the results processing, including best Model estimation, uncertainty analysis and plots generation. GravPSO2D is freely available, and represents an effort for providing the scientific community with the first tool based on the PSO algorithm in order perform the inversion and the uncertainty assessment of the sedimentary basin gravity inversion problem, taking into account the gravity regional trend estimation, and vertically and horizontally density contrast variations. Synthetic and real examples are provided in order to show the software capabilities.
J.l.g. Pallero - One of the best experts on this subject based on the ideXlab platform.
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GravPSO2D: A Matlab package for 2D gravity inversion in sedimentary basins using the Particle Swarm Optimization algorithm
Computers & Geosciences, 2021Co-Authors: J.l.g. Pallero, J.l. Fernández-martínez, Z. Fernández-muñiz, Sylvain Bonvalot, Germinal Gabalda, Thierry NalpasAbstract:In this paper GravPSO2D, a Matlab tool for two-dimensional gravity inversion in sedimentary basins using the Particle Swarm Optimization (PSO) algorithm, is presented. The package consists of a collection of functions and scripts that cover the main three parts of the process: (1) the Model Definition based on the observations, (2) the inversion itself, where the PSO is employed, and (3) the results processing, including best Model estimation, uncertainty analysis and plots generation. GravPSO2D is freely available, and represents an effort for providing the scientific community with the first tool based on the PSO algorithm in order perform the inversion and the uncertainty assessment of the sedimentary basin gravity inversion problem, taking into account the gravity regional trend estimation, and vertically and horizontally density contrast variations. Synthetic and real examples are provided in order to show the software capabilities.
Michael Beer - One of the best experts on this subject based on the ideXlab platform.
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operator norm theory as an efficient tool to propagate hybrid uncertainties and calculate imprecise probabilities
Mechanical Systems and Signal Processing, 2021Co-Authors: Matthias Faes, Marcos A Valdebenito, David Moens, Michael BeerAbstract:Abstract This paper presents a highly efficient and effective approach to bound the responses and probability of failure of linear systems where the Model parameters are subjected to combinations of epistemic and aleatory uncertainty. These combinations can take the form of imprecise probabilities or hybrid uncertainties. Typically, such computations involve solving a nested double loop problem, where the propagation of the aleatory uncertainty has to be performed for each realisation of the epistemic uncertainty. Apart from near-trivial cases, such computation is intractable without resorting to surrogate Modeling schemes. In this paper, a method is presented to break this double loop by virtue of the operator norm theorem. Indeed, in case linear Models are considered and under the restriction that the Model Definition cannot be subject to aleatory uncertainty, the paper shows that the computational efficiency, quantified by the required number of Model evaluations, of propagating these parametric uncertainties can be improved by several orders of magnitude. Two case studies involving a finite element Model of a clamped plate and a six-story building are included to illustrate the application of the developed technique, as well as its computational merit in comparison to existing double-loop approaches.
Graziano Salvalai - One of the best experts on this subject based on the ideXlab platform.
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overview of the available knowledge for the data Model Definition of a building renovation passport for non residential buildings the aldren project experience
Sustainability, 2020Co-Authors: Marta Maria Sesana, Mathieu Rivallain, Graziano SalvalaiAbstract:According to its strategic long-term vision, Europe wants to be a climate-neutral economy by 2050. Buildings play a crucial role in this vision, and they represent a sector with low-cost opportunities for high-level CO 2 reduction. The challenge the renovation of the existing building stock, which must be increased to 3%/year, more than double compared to the current 1.2%/year. In this context, the ALliance for Deep RENovation (ALDREN) project has the goal of encouraging property owners to undertake renovation of existing buildings using a clear, robust, and comparable method. This paper aims to present the ALDREN approach and the ALDREN Building Renovation Passport (BRP), giving an overview of the connections and data links to other existing databases and certification schemes. To understand the data value potential of buildings, one requires reliable and trustworthy information. The Building Renovation Passport, introduced by the recent Energy Performance Building Directive (EPBD) recast 844/2018/EU, aims to provide this information. This paper presents the experience of the ALDREN BRP for non-residential buildings as well as the development procedure for its data Model and the potential that this tool could have for the construction market. The ALDREN BRP has been structured into two main parts—BuildLog and RenoMap—with a common language that facilitates communication on the one hand and, on the other, the setting of renovation targets based on lifetime, operation, and user needs.