| 1. |
- Mattsson, Hans, et al.
(författare)
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On a constitutive driver as a useful tool in soil plasticity
- 1999
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Ingår i: Advances in Engineering Software. - 0965-9978 .- 1873-5339. ; 30:8, s. 511-528
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Tidskriftsartikel (refereegranskat)abstract
- A mathematical basis for the development of constitutive drivers in soil plasticity has been proposed by the authors. A constitutive driver is here understood as a computer program, containing a number of selected constitutive models, in which different laboratory and field tests can be simulated and model parameters optimised. As a pilot study of the mathematical concept, a constitutive driver for soils, in the form of a PC-program, has been developed. The paper discusses this particular program, i.e. its structure, the mathematical basis, included soil models and some application examples, to give an idea of how a general and user-friendly constitutive driver can be designed. Such a program can be used for practical, research and educational purposes. In fact, it is believed that so many important applications for constitutive drivers exist that it would be beneficial if such programs were easily accessible as complementary programs in commercial software.
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| 2. |
- Tisell, Claes, et al.
(författare)
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A system for multibody analysis based on object-relational database technology
- 2000
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Ingår i: Advances in Engineering Software. - 0965-9978 .- 1873-5339. ; 31, s. 971-984
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Tidskriftsartikel (refereegranskat)abstract
- An efficient support for computational technology and information management will be critical in future Engineering Information Systems (EIS). This paper shows how it is possible to provide efficient data management capabilities to the discipline of Multibody System (MBS) analysis. The MECHAMOS prototype of a MBS analysis tool has been developed that is based on an object-relational database management system, AMOS, which has been extended with additional mathematical functionality by the use of Matlab and MapleV as computational engines. The MBS model is represented as a database model in AMOS and the analysis is based on symbolic formulation of Kane's equations of motion. With this configuration, data is made fully accessible via the AMOSQL query language of AMOS. Furthermore, by providing the MBS application with general database technology, the data management will be more efficient in terms of handling large amounts of data and the development and maintenance of MBS analysis systems. Since MBS models are represented in a “neutral format”, the reusability of these models increases and they will be more persistent to changes in the EIS environment.
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| 3. |
- Abdeljaber, Osama, et al.
(författare)
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A novel video-vibration monitoring system for walking pattern identification on floors
- 2020
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Ingår i: Advances in Engineering Software. - : Elsevier. - 0965-9978 .- 1873-5339. ; 139
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Tidskriftsartikel (refereegranskat)abstract
- Walking-induced loads on office floors can generate unwanted vibrations. The current multi-person loading models are limited since they do not take into account nondeterministic factors such as pacing rates, walking paths, obstacles in walking paths, busyness of floors, stride lengths, and interactions among the occupants. This study proposes a novel video-vibration monitoring system to investigate the complex human walking patterns on floors. The system is capable of capturing occupant movements on the floor with cameras, and extracting walking trajectories using image processing techniques. To demonstrate its capabilities, the system was installed on a real office floor and resulting trajectories were statistically analyzed to identify the actual walking patterns, paths, pacing rates, and busyness of the floor with respect to time. The correlation between the vibration levels measured by the wireless sensors and the trajectories extracted from the video recordings were also investigated. The results showed that the proposed video-vibration monitoring system has strong potential to be used in training data-driven crowd models, which can be used in future studies to generate realistic multi-person loading scenarios.
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| 4. |
- Andersson, Håkan, et al.
(författare)
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Validation of a co-simulation approach for hydraulic percussion units applied to a hydraulic hammer
- 2019
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Ingår i: Advances in Engineering Software. - : ELSEVIER SCI LTD. - 0965-9978 .- 1873-5339. ; 131, s. 102-115
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Tidskriftsartikel (refereegranskat)abstract
- In this study, a previously developed co-simulation approach has been adopted to simulate the responses of an existing hydraulic hammer product. This approach is based on a 1D system model representing the fluid components and a 3D finite element model representing the structural parts of the hydraulic hammer. The simulation model was validated against four experiments with different running conditions. The corresponding set-ups were analysed using the co-simulation method in order to evaluate the overall responses. A parameter study was also performed involving the working pressure and the restrictor diameter, with the objective to validate that a parameter change in the simulation model will affect the input and output power in the same direction as in the experiments. The experimental responses used in the validation were time history data of fluid pressure, component position and acceleration, and structural stresses. The experiments result in high frequency and high amplitude excitations of the hydraulic hammer and thus require a model with a high resolution of the model dynamics. The conclusion of the validation is that the simulation model is able to replicate the experimental responses with high accuracy including the high frequency dynamics. The favourable outcome of the validation makes the described co-simulation approach promising as an efficient tool for a wide range of other applications where short time duration mechanisms need to be studied.
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| 5. |
- Biel, Martin, et al.
(författare)
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POLO.Jl : Policy-based optimization algorithms in Julia
- 2019
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Ingår i: Advances in Engineering Software. - : Elsevier. - 0965-9978 .- 1873-5339. ; 136
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Tidskriftsartikel (refereegranskat)abstract
- We present POLO. j1- a Julia package that helps algorithm developers and machine-learning practitioners design and use state-of-the-art parallel optimization algorithms in a flexible and efficient way. POLO. j1 extends our C+ + library POLO, which has been designed and implemented with the same intentions. POLO. j1 not only wraps selected algorithms in POLO and provides an easy mechanism to use data manipulation facilities and loss function definitions in Julia together with the underlying compiled C+ + library, but it also uses the policy-based design technique in a Julian way to help users prototype optimization algorithms from their own building blocks. In our experiments, we observe that there is little overhead when using the compiled C+ + code directly within Julia. We also notice that the performance of algorithms implemented in pure Julia is comparable with that of their C+ + counterparts. Both libraries are hosted on GitHub(1)under the free MIT license, and can be used easily by pulling the pre-built 64-bit architecture Docker images.(2)
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| 6. |
- Bulik, M., et al.
(författare)
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Stochastic simulation for crashworthiness
- 2004
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Ingår i: Advances in Engineering Software. - : Elsevier Ltd. - 0965-9978 .- 1873-5339. ; 35:12, s. 791-803
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Tidskriftsartikel (refereegranskat)abstract
- This paper describes the M-Xplore extension of the Radioss software. The module contains facilities for the exploration of a parameterized finite element model design space. It supports facilities for interactive choice of variables and responses, definition of a sampling on a design space, automatic submission of the computations, and post-processing of the results. The computations are run automatically, either locally or in ASP-mode, i.e. as a client of a high-performance computing server. The software is described first in general, then we illustrate its exploration possibilities in terms of a model problem and a more typical application problem of crash simulation
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| 7. |
- Burger, Gregor, et al.
(författare)
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Designing and implementing a multi-core capable integrated urban drainage modelling Toolkit : Lessons from CityDrain3
- 2016
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Ingår i: Advances in Engineering Software. - : Elsevier BV. - 0965-9978 .- 1873-5339. ; 100, s. 277-289
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Tidskriftsartikel (refereegranskat)abstract
- Integrated urban drainage modelling combines different aspects of the urban water system into a common framework. With increasing pressures of a changing climate, urban growth and economic constraints, the need for wider spread integration is necessary in the interest of a sustainable future. Greater complexity results in greater computational burden but modelling packages will, likewise, need to be flexible enough to allow incorporation of new algorithms. With advancements in modern information technology, a parallel implementation of such a modelling toolkit is mandatory while still leaving its users the flexibility of extensions. The design and implementation of the integrated modelling framework CityDrain3 shows that it is possible to write research code that is high-performance and extensible by many research projects. Three use case scenarios are presented to showcase the application of CityDrain3. The performance advantage of parallelization (up to 40 times compared to its predecessor) and the scalability of the framework are also demonstrated.
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| 8. |
- Dai, Xu, et al.
(författare)
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An engineering CFD model for fire spread on wood cribs for travelling fires
- 2022
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Ingår i: Advances in Engineering Software. - : Elsevier Ltd. - 0965-9978 .- 1873-5339. ; 173
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Tidskriftsartikel (refereegranskat)abstract
- The temperature heterogeneity due to fire in large open-plan office compartments is closely associated with fire spread behaviour and has been historically limited to experimental investigations using timber cribs. This study explores the ability of Computational Fluid Dynamics (CFD) models, specifically the Fire Dynamics Simulator (FDS), to reproduce the results of full-scale tests involving fire spread over timber cribs for continuous fuel-beds. Mesh schemes are studied, with a fine mesh over the crib and 2 × 2 cells in the wood stick cross-section by default, this being relaxed in the surrounding regions to enhance computational efficiency. The simple pyrolysis model considers the charring phase and moisture. In application to the TRAFIR-Liège LB7 test, this calibrated “stick-by-stick” representation shows a good agreement for interrelated parameters of heat release rate, fire spread, gas phase temperature, and burn-away, a set of agreements which has not been demonstrated in previous studies. Fire spread shows relatively high sensitivities to: heat of combustion, ignition temperature, thermal inertia, radiation fraction, heat release rate per unit area, and the fuel load density. An approximately linear regression was found between the different fire modes and the thermal exposures, with “travelling” (and decaying) fires characterised by heat fluxes associated with the fire plume, while the growing fires were associated with proportionally higher heat fluxes on the horizontal surfaces of the sticks, in conditions where these receive more pre-heating. The trends in the overall HRR are more dependent on the fire spread rates than variations in the stick burning rates. © 2022 The Author(s)
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| 9. |
- Eriksson, Anders, 1953-, et al.
(författare)
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Engineering computational technology
- 2007
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Ingår i: Advances in Engineering Software. - : Elsevier BV. - 0965-9978 .- 1873-5339. ; 38:11-12, s. 723-725
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Tidskriftsartikel (refereegranskat)
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| 10. |
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| 11. |
- Haoxue, Ma, et al.
(författare)
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Distribution and synchronisation of engineering information using active database technology
- 2005
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Ingår i: Advances in Engineering Software. - : Elsevier BV. - 0965-9978 .- 1873-5339. ; 36:11-12, s. 720-728
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Tidskriftsartikel (refereegranskat)abstract
- Today, work collaboration is normal practice in developing modern products. Engineering collaborative work involves a number of team members that need to share and exchange design ideas while working with engineering analysis tools such as mechanical computer aided engineering systems. This work presents the M-Sync prototype system that uses an active database approach to enable exchange of engineering information among distributed team members in a timely manner. The distributed data is fully accessible by the local member and is automatically synchronised between different places using a database management system that support event-condition-action (ECA) database rules. Only updates introduced at one location are distributed to other locations, thereby minimizing information transfer and enhancing performance. Members working at different locations can therefore work in a peer-to-peer (P2P) manner and interactively manipulate the same set of information at the same time.
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| 12. |
- Hellström, Gunnar, et al.
(författare)
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Parallel CFD simulations of an original and redesigned hydraulic turbine draft tube
- 2007
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Ingår i: Advances in Engineering Software. - : Elsevier BV. - 0965-9978 .- 1873-5339. ; 38:5, s. 338-344
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Tidskriftsartikel (refereegranskat)abstract
- The design of hydraulic turbine draft tubes has traditionally been based on simplified analytic methods, model and full-scale experiments. In the recent years the use of numerical methods such as computational fluid dynamics (CFD) has increased in the design process, due to the rapid escalation in computer performance. Today with parallel computer architectures, new aspects of flow can be considered. However, several problems have still to be solved before CFD can routinely be applied in product development. This paper aims to investigate the parallel performance of commercial CFD software on homogeneous computer networks, as common solutions encountered in the industry today. In addition, the efficiency improvements obtained in earlier experiments by modifying the shape of the draft tube will be considered, to deduce if the improvements can be captured with aid of CFD. Results from both the steady and the unsteady CFD simulations show that almost full scalability is obtained with the commercial CFD software CFX-5.7.1. Furthermore, no noticeable improvement in the pressure recovery factor or the flow field is noticed in the CFD simulations as compared to experiments. The discrepancy may be to the applied inlet boundary conditions and/or the turbulence model.
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| 13. |
- Innocenti, M. E., et al.
(författare)
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Progress towards physics-based space weather forecasting with exascale computing
- 2017
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Ingår i: Advances in Engineering Software. - : Elsevier. - 0965-9978 .- 1873-5339. ; 111, s. 3-17
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Tidskriftsartikel (refereegranskat)abstract
- Space weather is a rapidly growing field of science which studies processes occurring in the area of space between the Sun and the Earth. The development of space weather forecasting capabilities is a task of great societal relevance: space weather effects may damage a number of technological assets, among which power and communication lines, transformers, pipelines and the telecommunication infrastructure. Exascale computing is a fundamental ingredient for space weather forecasting tools based on physical, rather than statistical, models. We describe here our recent progresses towards a physics-based space weather forecasting tool with exascale computing. We select the semi-implicit, Particle In Cell, Implicit Moment Method implemented in the parallel, object-oriented, C++ iPic3D code as a promising starting point. We analyze the structure and the performances of the current version of the iPic3D code. We describe three algorithmic developments, the fully implicit method, the Multi-Level Multi-Domain method, and the fluid-kinetic method, which can help addressing the multiple spatial and temporal scales present in space weather simulations. We then examine, in a co-design approach, which requirements - vectorization, extreme parallelism and reduced communication - an application has to satisfy to fully exploit architectures such as GPUs and Xeon Phi's. We address how to modify the iPic3D code to better satisfy these requirements. We then describe how to port the iPic3D code to the DEEP architecture currently under construction. The FP7 project DEEP (www.deep-project.eu) aims at building an exascale-ready machine composed of a cluster of Xeon nodes and of a collection of Xeon Phi coprocessors, used as boosters. The aim of the DEEP project is to enable exascale performance for codes, such as iPic3D, composed of parts which exhibit different potential for extreme scalability. Finally, we provide examples of simulations of space weather processes done with the current version of the iPic3D code.
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| 14. |
- Jin, Junchen, et al.
(författare)
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A stochastic optimization framework for road traffic controls based on evolutionary algorithms and traffic simulation
- 2017
-
Ingår i: Advances in Engineering Software. - : Elsevier. - 0965-9978 .- 1873-5339. ; 114, s. 348-360
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Tidskriftsartikel (refereegranskat)abstract
- Traffic flow is considered as a stochastic process in road traffic modeling. Computer simulation is a widely used tool to represent traffic system in engineering applications. The increased traffic congestion in urban areas and their impacts require more efficient controls and management. While the effectiveness of control schemes highly depends on accurate traffic model and appropriate control settings, optimization techniques play a central role for determining the control parameters in traffic planning and management applications. However, there is still a lack of research effort on the scientific computing framework for optimizing traffic control and operations and facilitating real planning and management applications. To this end, the present study proposes a model-based optimization framework to integrate essential components for solving road traffic control problems in general. In particular, the framework is based on traffic simulation models, while the solution needs extensive computation during the engineering optimization process. In this work, an advanced genetic algorithm, extended by an external archive for storing globally elite genes, governs the computing framework, and in application it is further enhanced by a sampling approach for initial population and utilizations of adaptive crossover and mutation probabilities. The final algorithm shows superior performance than the ordinary genetic algorithm because of the reduced number of fitness function evaluations in engineering applications. To evaluate the optimization algorithm and validate the whole software framework, this paper illustrates a detailed application for optimization of traffic light controls. The study optimizes a simple road network of two intersections in Stockholm to demonstrate the model-based optimization processes as well as to evaluate the presented algorithm and software performance.
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| 15. |
- Johansson, Henrik, et al.
(författare)
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A system for information management in simulation of manufacturing processes
- 2004
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Ingår i: Advances in Engineering Software. - : Elsevier BV. - 0965-9978 .- 1873-5339. ; 35:10-11, s. 725-733
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Tidskriftsartikel (refereegranskat)abstract
- A system has been developed to manage simulation information of manufacturing processes, such as mesh information, boundary conditions and process parameters. The goal is to enable information sharing and exchange to make it possible to simulate a whole chain of manufacturing processes, and thereby predict how a modification in one manufacturing process affects the characteristics of the final product. The system has been used to predict successful simulation of a cutting process using mesh information and process parameters. An object-relational database management system is embedded in the system that uses a conceptual EXPRESS schema as database schema. The database management system is lightweight main-memory resident and incorporates an extensible and object-oriented query language. Uniform storage using database technology enables information manipulation independently of any specific simulation tool.
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| 16. |
- Liu, Bokai, et al.
(författare)
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Al-DeMat: A web-based expert system platform for computationally expensive models in materials design
- 2023
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Ingår i: Advances in Engineering Software. - : Elsevier. - 0965-9978 .- 1873-5339. ; 176
-
Tidskriftsartikel (refereegranskat)abstract
- We present a web-based framework based on the R shiny package with functional back-end server in machine learning methods. A 4-tiers architecture is programmed to achieve users’ interactive design and visualization via a web browser. Many data-driven methods are integrated into this framework, namely Random Forest, Gradient Boosting Machine, Artificial and Deep neural networks. Moreover, a robust gradient-free optimization technique, the Particle Swarm Optimization, is used to search optimal values in hyper-parameters tuning. K-fold Cross Validation is applied to avoid over-fitting. R2 and RMSE are considered as two key factors to evaluate the trained models. The contributions to the expert system in materials design are: (1) A systematic framework that can be applied in materials prediction with machine learning approaches, (2) A user-friendly web-based platform that is easy and flexible to use and (3) integrated optimization and visualization into the framework with pre set algorithms. This computational framework is designed for researchers and materials engineers who would like to do the preliminary designs before experimental studies. Finally, we demonstrate the performance of the web-based framework through 2 case studies.
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| 17. |
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| 18. |
- Logg, Anders, 1976, et al.
(författare)
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Finite element simulation of physical systems in augmented reality
- 2020
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Ingår i: Advances in Engineering Software. - : Elsevier BV. - 0965-9978 .- 1873-5339. ; 149
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Tidskriftsartikel (refereegranskat)abstract
- We present a system for immersive and interactive physics simulation in augmented reality, implemented as an application on the Microsoft HoloLens. The system allows a user to simulate physical phenomena in real-world geometries by scanning the surroundings and automatically creating a finite element discretization (mesh). The system also provides a user interface based on voice commands for specification of boundary conditions and source terms, and for immersive visualization of simulation results. All computations are carried out on the HoloLens. The current implementation, named HoloFEM, demonstrates the application of augmented reality simulation for the time-dependent advection-diffusion equation. In the current work, we consider a simplified model problem with simplified parameters and data. The model is however still conceptually applicable to the simulation of indoor climate (temperature and air quality), which has implications for interactive HVAC (heating, ventilation, and air conditioning) simulation.
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| 19. |
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| 20. |
- Mackerle, Jaroslav
(författare)
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Object-oriented programming in FEM and BEM : A bibliography (1990-2003)
- 2004
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Ingår i: Advances in Engineering Software. - : Elsevier BV. - 0965-9978 .- 1873-5339. ; 35:6, s. 325-336
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Tidskriftsartikel (refereegranskat)abstract
- This paper gives a bibliographical review of the object-oriented programming applied to the finite element method as well as to the boundary element method. The bibliography at the end of the paper contains references to papers, conference proceedings and theses/dissertations on the subject that were published between 1990 and 2003. The following topics are included: finite element method - object-oriented programming philosophy, mesh modelling, distributed/parallel processing, toolkits and libraries, object-oriented specific applications (aerospace, civil engineering/geomechanics, coupled problems, dynamical systems, electromagnetics, fracture mechanics and contact problems, material simulations/manufacturing, mechanical engineering, nonlinear structural simulations, optimization, others), boundary element method. Totally 408 references are listed. © 2004 Elsevier Ltd. All rights reserved.
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| 21. |
- Nakkeeran, G., et al.
(författare)
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Machine learning application to predict the mechanical properties of glass fiber mortar
- 2023
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Ingår i: Advances in Engineering Software. - : Elsevier. - 0965-9978 .- 1873-5339. ; 180
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Tidskriftsartikel (refereegranskat)abstract
- In this study, the mechanical properties of concrete mortars have been predicted using machine learning tools, Response Surface Methodology (RSM), and Artificial Neural Network (ANN) approach. This study focused on mortar, in which cement has been partially replaced by 20% fly ash (FA) and 20% hydrated lime. In the experiment, the compressive strength (CS) of mortar has determined after curing the mix for 7 and 28 days, respectively. Glass fiber was added in the proportions of 0%, 0.2%, 0.4%, 0.6%, 0.8%, and 1% by weight of concrete to the mortar accordingly. The compressive strength of mortar incorporated with glassfiber increases according to an increase in the proportion of the glass fiber. Results indicates that the optimal fiber proportion of the glass fiber in the mortar had been observed to be 0.6%. The predicted compressive strength at day 28 has been modeled using RSM and ANN. The RSM model has been used to predict mechanical properties (R2 ≥ 0.7534) accurately. Furthermore, the appropriate R threshold (R > 0.999) for training, testing, and validation demonstrates that the ANN model has successfully captured the variability in the data. The results show that with the high correlation between the experimental and prediction results in data, more accuracy has been observed in the ANN model than in the RSM model.
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| 22. |
- Nyström, Mattias, et al.
(författare)
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Computational database technology for component mode synthesis
- 2004
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Ingår i: Advances in Engineering Software. - : Elsevier BV. - 0965-9978 .- 1873-5339. ; 35:10-11, s. 735-45
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Tidskriftsartikel (refereegranskat)abstract
- The present work show how object relational database management system technology can be used to support an finite element analysis process that includes component mode synthesis using the Craig–Bampton method for calculating reduced mass and stiffness matrices. A general object-oriented model for accessing matrix data independent of matrix representation is presented. The model is used to express the calculations of the reduced stiffness and mass matrices in a declarative query language and thereby letting the database decide how to execute the operations and manage the memory.
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| 23. |
- Olofsson, Jakob, et al.
(författare)
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A methodology for microstructure-based structural optimization of cast and injection moulded parts using knowledge-based design automation
- 2017
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Ingår i: Advances in Engineering Software. - : Elsevier. - 0965-9978 .- 1873-5339. ; 109, s. 44-52
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Tidskriftsartikel (refereegranskat)abstract
- The local material behaviour of cast metal and injection moulded parts is highly related to the geometrical design of the part as well as to a large number of process parameters. In order to use structural optimization methods to find the geometry that gives the best possible performance, both the geometry and the effect of the production process on the local material behaviour thus has to be considered. In this work, a multidisciplinary methodology to consider local microstructure-based material behaviour in optimizations of the design of engineering structures is presented. By adopting a knowledge based industrial product realisation perspective combined with a previously presented simulation strategy for microstructure-based material behaviour in Finite Element Analyses (FEA), the methodology integrates Computer Aided Design (CAD), casting and injection moulding simulations, FEA, design automation and a multi-objective optimization scheme into a novel structural optimization method for cast metal and injection moulded polymeric parts. The different concepts and modules in the methodology are described, their implementation into a prototype software is outlined, and the application and relevance of the methodology is discussed.
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| 24. |
- Blennow, Mattias, et al.
(författare)
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RG running in a minimal UED model in light of recent LHC Higgs mass bounds
- 2012
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Ingår i: Physics Letters B. - : Elsevier. - 0370-2693 .- 1873-2445. ; 712:4-5, s. 419-424
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Tidskriftsartikel (refereegranskat)abstract
- We study how the recent ATLAS and CMS Higgs mass bounds affect the renormalization group running of the physical parameters in universal extra dimensions. Using the running of the Higgs self-coupling constant, we derive bounds on the cutoff scale of the extra-dimensional theory itself. We show that the running of physical parameters, such as the fermion masses and the CKM mixing matrix, is significantly restricted by these bounds. In particular, we find that the running of the gauge couplings cannot be sufficient to allow gauge unification at the cutoff scale.
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