Abstract: Publication date: April 2019Source: Advances in Engineering Software, Volume 130Author(s): Zhanping Liu Scientific visualization seeks to provide deep insight into the complex pattern underlying big data, while flow visualization plays a crucial role in oceanographic-atmospheric modeling and computational fluid dynamics simulation. As an increasingly important strategy, parallel visualization incorporates data visualization with parallel computing by means of MPI (Message Passing Interface) to achieve efficient visual analysis to facilitate scientific study. This paper presents a prototype framework for parallel visualization of large flow data, involving MPI as the low-level parallel computing paradigm, DIY (Do It Yourself) as a block-oriented data-parallel programming library on top of MPI, OSUFlow as a geometry-based flow visualization engine, and VTK (Visualization Toolkit) for data input, graphics rendering, and scene interaction. It exposes the combined power of DIY and OSUFlow, including parallel yet seamless generation of streamlines as well as pathlines from vector data defined on Cartesian, rectilinear, and curvilinear grids, to a broad community of high-performance flow visualization through VTK. Preliminary results show that this framework is capable of exploiting the horsepower of a vast number of processors to accelerate data processing and visualization for explorative analysis of massive steady/unsteady volume flows.

Abstract: Publication date: April 2019Source: Advances in Engineering Software, Volume 130Author(s): Klaus-Jürgen Bathe The objective in this paper is to largely review, but also give new insight into, the recent development of a novel paradigm for finite element analysis. The approach enables much easier meshing than usually performed for finite element analysis and then the computationally efficient solution of the finite element model. The important aspects of the paradigm are the automatic meshing on any given geometry (typically given by use of a CAD program or a computerized scan) with the use of overlapping and regular finite elements – hence the acronym AMORE for Automatic Meshing with Overlapping and Regular Elements. We summarize the basic steps used in the paradigm, give the basic equations to formulate the overlapping elements, discuss specific attributes, give some applications and conjecture on the further development and use of the solution scheme. Our discussion is based on previously published work with a focus on simplifying the formulation of the overlapping elements, providing novel insight, and suggesting a notation. The paradigm has so far only been applied in the linear analyses of solids, however embodies significant potential for general and wide use in computer-aided engineering.

Abstract: Publication date: March 2019Source: Advances in Engineering Software, Volume 129Author(s): Peter Vernarsky, Michal Tomko, Robert Soltys, Stanislav Kmet Numerical simulations of wind circumfluence around Tensairity cylindrical beams and predictions of their response are presented in the paper. An appropriate computational fluid dynamics model (CFD) and a fluid-structure interaction (FSI) method are used to study circumfluent wind fields and wind-induced vibrations of the Tensairity cylindrical beams. Navier-Stokes equations for the incompressible fluid dynamic simulations and FSI analysis of the Tensairity cylindrical beam subjected to the wind flow are applied. Constant and simulated fluctuating wind fields were assigned to the investigated structure. A Spalart-Allmaras (SA) one-equation turbulence model that uses an eddy-viscosity variable with a nonlinear transport equation was applied in the CFD analysis. The finite element method is used to simulate the aeroelastic behavior of the Tensairity cylindrical beam subjected to constant and fluctuating wind effects. Aeroelastic response characterized by wind velocity fields and vortex-shedding phenomena around the cross-section of the inflatable structure are presented. Results obtained from the CFD and FSI analysis were compared. The vortex shedding effects may produce significant lateral (cross-wind) vibrations with nonlinear redistributions of forces and displacements as well as introduce additional deformations to the individual structural members of the Tensairity system. The wind-structure interaction analysis of the Tensairity cylindrical beam revealed, in particular, the sensitivity of the pneumatic structure to vortex induced vibrations with galloping effects.

Abstract: Publication date: March 2019Source: Advances in Engineering Software, Volume 129Author(s): Pu Li, Haiyan Li, Yunbao Huang, Senquan Yang, Haitian Yang, Yuesheng Liu Product optimization requires many times of simulation which is often time-consuming. The sparse response surface, which is constructed over single orthogonal polynomial bases and sparse coefficients from a few samplings, is employed to reduce simulation times. However, it still requires many samplings for response surface of complex products.In this paper, a High Sparse Response Surface (HSRS) method based on combined bases is proposed with the following main contributions: (1) compared with a single base, a base dictionary is combined with a variety of different base functions, and maybe construct sparser response surface by less expressive bases, which reduced the number of sampling and improved the approximation accuracy, (2) ℓp-norm (p=1/2) minimum solution, which is calculated by the Conjugate Gradient-FOCal Underdetermined System Solver (CG-FOCUSS) method, is used to approximate the sparest solution through calculating cost and coefficient sparsity trade-off, and (3) cross-validation is employed to select good initial value to obtain approximation optimal solution, which reduces the influence of the initial value on the CG-FOCUSS algorithm result.Finally, HSRS is applied to three benchmark test functions and two engineering problem, and the results are compared with the single base sparse response surface. The results show that (1) about 14.3% to 44.4% sample points can be reduced for HSRS to achieve the same accuracy of single base sparse response surface, (2) the accuracy of HSRS with cross-validation can be increased by about 20.31% to 40.81%.

Abstract: Publication date: Available online 17 January 2019Source: Advances in Engineering SoftwareAuthor(s): Ruixiang Bai, Zhenfei Guo, Zhenkun Lei, Wen Wu, Cheng Yan In order to efficiently predict the welding deformation of large and complex welded structures based on the inherent deformation method, it is necessary to obtain the inherent deformations of each weld seam beforehand. In this paper, a new method was proposed to inverse inherent deformations by combining inherent deformation method and complex method. The validity of the proposed hybrid inversion method was proved by the comparison with the results of thermal-elastic-plastic (TEP) model the effectiveness of which had been demonstrated by the welding deformation and residual stress obtained from the butt-welded experiment. And the independence of the method on initial value is verified by inversion results using different initial complex shapes. Finally, the sensitivity analysis of inherent deformations was also carried out, and the analysis result shows that longitudinal shrinkage, transverse shrinkage and transverse curvature have a more significant effect on calculation accuracy than longitudinal curvature for the present welded plates.

Abstract: Publication date: Available online 12 January 2019Source: Advances in Engineering SoftwareAuthor(s): M. Occelli, T. Elguedj, S. Bouabdallah, L. Morançay IsoGeometric Analysis has shown to be a very promising tool for an integrated design and analysis process. A challenging task is still to move IGA from a proof of concept to a convenient design tool for industry and this work contributes to this endeavor. This paper deals with the implementation of the IGA concept into Altair Radioss finite element solver in order to address crash and stamping simulation applications. To this end, the necessary ingredients to a smooth integration of IGA in a traditional finite element code have been identified and adapted to the existing code architecture. A solid B-Spline element has been developed in Altair Radioss and then, an existing contact interface has been extended in order to work seamlessly with both NURBS and Lagrange finite elements. As local refinement is needed for solution approximation, an analysis is made in terms of analysis suitability and implementation aspects for several Spline technologies. The Locally Refined B-Spline (LRBS) technology is implemented and is validated on industrial benchmarks, for validation cases conventionally used for industrial codes like stamping and drop test.

Abstract: Publication date: Available online 8 January 2019Source: Advances in Engineering SoftwareAuthor(s): Zhao Tang, Xiaolin Yuan, Xin Xie, Jie Jiang, Jianjun Zhang In terms of simulation efficiency, modelling and visualization, general-purpose multibody simulation (GPMBS) software packages have a lot of inherent advantages compared with specialized railway vehicle dynamics simulation software packages. However, their application is limited due to the absence of specialized force elements and contact models, and thus cannot be directly employed for railway vehicle dynamics simulation. To deal with this issue, this paper proposes a novel framework to use GPMBS software packages to simulate the dynamic behavior of the railway vehicle. This framework contains a loose coupling method, a sub-mechanism feature and a top-down modelling method and allows users to take full advantage of the advanced functionalities of the GPMBS software packages to improve the efficiency of railway vehicle dynamics simulation. The feasibility of this framework is verified by integrating extensions for two representative GPMBS software packages. In addition, the two comparisons between the self-developed extensions (for LMS Virtual.Lab Motion and Unity3D) and the widely used specialized railway vehicle dynamics simulation software (Simpack and Universal Mechanism), further confirm the validity of the framework.

Abstract: Publication date: Available online 6 January 2019Source: Advances in Engineering SoftwareAuthor(s): Weiyuan Dou, Lele Zhang, Geng Chen, Wenjie Zhu In fluid-structure interaction (FSI) problems, accuracy of the data transfer between fluid-structure interfaces is mainly attributed to the element type and discretization density of grids in both fluid and structure domains. To remedy the inaccuracy caused by the prevalently applied solo elemental node interpolation strategy, a novel interpolation method is proposed in the present study. The approach is based on the radial basis function and introduces a weight coefficient through which the centroid and nodes of an element are joined. This way, the interpolation will be conducted in accordance to a weighted summation of both terms. Before it is applied to practice relevant engineering examples, the validity of the formulated approach is first examined by simple 2D and further 3D case studies. Studies have clearly illustrated that, compared to pure element centroid or nodes based interpolation schemes, the established approach is insensitive to the pressure distribution. Meanwhile, in these cases the influence of selected basis functions and mesh densities have been examined in detail. Based on the knowledge gained from these case studies, it further investigated a problem emerged from high-speed trains in which the CFD simulation is validated by the field experiment and the task is to transfer data from the fluid domain to the structure domain. Result of the study shows that for the high speed train model considered which has complicated non-matching grids, the accuracy of data transfer in fluid-structure interaction is highly improved and the maximum of global relative error achieves 2.62%.

Abstract: Publication date: Available online 30 December 2018Source: Advances in Engineering SoftwareAuthor(s): T. Garcia, P. Spiteri, G. Khenniche This paper presents the behavior of general parallel synchronous and asynchronous multisplitting and two-stage methods for the numerical simulation of steel solidification in continuous casting. Thanks to the mathematical analysis and the implementation of these methods one can show the results of parallel experiments for the target application. The mathematical model is constituted by coupled nonlinear boundary value problems, namely the heat equation taking into account, on part of the boundary, a radiation phenomenon described by the Stefan law. For the numerical solution of such partial differential equations we consider, depending on whether the coefficient of thermal conductivity is constant or temperature-dependent, both an implicit or a semi-implicit discretization with respect to the time of the studied evolution problem, while the spatial discretization is carried out by adapted finite difference schemes. Then large scale discretized algebraic systems are solved by sequential and synchronous or asynchronous iterative algorithms; comparison of these various previous methods implemented on clusters and grid are achieved in both cases when the thermal conductivity is constant and more generally dependent of the temperature.

Abstract: Publication date: Available online 28 December 2018Source: Advances in Engineering SoftwareAuthor(s): H. Andersson, K. Simonsson, D. Hilding, M. Schill, E. Sigfridsson, D. Leidermark 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.

Abstract: Publication date: Available online 27 December 2018Source: Advances in Engineering SoftwareAuthor(s): Cícero R. de Lima, Glaucio H. Paulino Compliant mechanisms are monolithic structures where the movement is given by the flexibility of the structure rather than the presence of joints and pins. The absence of joints allows the construction of compliant mechanisms in microscale. In this work, the compliant mechanism is designed by using topology optimization to generate microstructure unit cells that simulate the effect of auxetic materials, i.e. those with negative Poisson's ratio. Polygonal finite element meshes are introduced in the topology optimization formulation to avoid the hinges (one-node connections) in the compliant mechanism design. A pattern repetition constraint is applied to generate auxetic macrostructures. An integrated approach that combines a projection technique with a mapping technique is adopted to include the minimum member size constraint, making the topology optimization results possible to be manufactured. The connection of the topology optimization approach with additive manufacturing is demonstrated using 3D printers based on FFF (fused filament fabrication) and PolyJet technologies. Thus, computational simulation in connection with rapid prototyping are carried out to verify the results.

Abstract: Publication date: Available online 24 November 2018Source: Advances in Engineering SoftwareAuthor(s): Jiří Tomčala, Jan Papuga, David Horák, Václav Hapla, Marek Pecha, Martin Čermák This paper describes various methods for increasing the computational speed of an existing fatigue solver called PragTic. The paper describes the basic workflow of computational fatigue analysis, including multiaxial fatigue analysis as well. It documents some of the inefficiencies of the original PragTic version, and parallelization and scalability testing of the parallelized PragTic in three different case studies. These studies include a simple model example (hundreds of nodes) and a real world example (millions of nodes). The implemented parallelization techniques are tested using numerical experiments to demonstrate their parallel scalability. As an output of a unique analysis, the number of necessary and feasible evaluated planes in multiaxial analyses is monitored, and the outcome favoring integral methods for the multiaxial fatigue analysis is commented.

Abstract: Publication date: Available online 23 November 2018Source: Advances in Engineering SoftwareAuthor(s): She Li, Li Tian, Xiangyang Cui In this work, the phase-field modeling is formulated in the framework of cell-based smoothed finite element method for predicting the crack propagation in solids. Unlike the description of cracks as sharp surfaces, an exponential function is introduced to approximate the diffuse crack topology. The order parameter with continuous values changes from 0 to 1, which is employed to distinguish the broken and unbroken materials. The present modeling for crack propagation links damage and fracture mechanics. Every node on each element has two (or three) displacement and one phase-field DOFs. Cell-based smoothed finite element method is employed to solve the coupled elastic displacement and phase-field fracture problem. Several numerical tests are employed to validate the feasibility of present modeling. Numerical results obtained by the proposed modeling are in good accordance with the analytic one or the other methods. Meanwhile, the method can be easily embedded in the commercial software ABAQUS with user defined subroutines. In order to offer convenience for engineers, a user-friendly interface for ABAQUS is established based on Qt. One can establish input file conveniently without professional knowledge. Its attractive features produce potential for further study.

Abstract: Publication date: Available online 8 July 2018Source: Advances in Engineering SoftwareAuthor(s): Tomáš Brzobohatý, Marta Jarošová, Radek Kučera, Václav Šátek A path-following interior point method is proposed for minimization of quadratic functions subject to box and equality constraints. The problems with the singular Hessian that is symmetric, positive definite on the null space of the equality constraint matrix are considered. The inner linear systems are solved by the projected conjugate gradient method preconditioned by oblique projectors. Numerical experiments include large-scale problems arising from the TFETI domain decomposition method applied for solving the Stokes flow with the stick-slip boundary condition.

Abstract: Publication date: Available online 19 January 2007Source: Advances in Engineering SoftwareAuthor(s): T.T. Tanyimboh, A.B. TemplemanThis article has been removed consistent with Elsevier Policy on Article Withdrawal. The Publisher apologises for any inconvenience this may cause.