A smooth contact force, as expected for the quasi static case, is obtained for t 20. Mass scaling for quasistatic analyses is usually performed on the entire. The commercial code abaqus is the main tool used for the fem analysis in the. In this article, our focus is on increased load rates approach.
Abaqus is often applied to solve geomechanical boundary value problems. The key theoretical aspects of an explicit solver are presented, together with the numerical challenges faced when applied to solving quasi static problems. Introduction quasi static simulations using explicit dynamics loading rates energy balance in quasi static analyses mass scaling viscous pressure summary challenging nonlinear quasi static problems often involve. Use the explicit dynamics method effectively, including the application of general contact, mass scaling, and adaptive remeshing. In the first supplemental analysis, mass scaling was used to increase the critical time increment size for the elements by a factor of 10 mass increased by 100. How step time increment can be increased in abaqusexplicit. For quasi static analyses, the total time simulated can sometimes be reduced by applying the load faster. In this study, the dynamic analysis using abaqus explicit is employed to model the end plate connections under quasi static loading. Massgravityscaling technique to enhance computational. Therefore, based on newton law the sum of all forces is. Pdf abaqus analysis users manual prakash k academia.
This workshop involves simulating quasi static rolling of a plate using abaqus explicit. Explicit dynamic formulation to demonstrate compliance. I have read a few papers, especially the ones that have been written on sheet metal forming and they quote the same. With this training course you will learn practical skills and best practices for performing dynamic and quasi static analyses with abaqus explicit including general contact, mass scaling, adaptive meshing, output filtering, material. Technical white paper hp workstations and simulia abaqus from. Quasi static analysis is a useful tool for studying systems which undergo very large deformations. For quasi static analysis, the value of time increment is adjusted based on these criteria. Significant discrepancies in the final shape of the workpiece are found. Furthermore, assume that even after being scaled by a factor of 50, a few extremely small or poorly shaped elements are causing the stable. The time increment in an explicit analysis is calculated from an characteristic dimension of. The use of mgs technique will be demonstrated in three quasi static soilstructure problems of tbar penetrometer, spudcanpile interaction, and pilereinforced slope. Artificially increasing the material density mass scaling by a factor of f 2, increases the analysis speed by a factor of f. Figure 2 shows the contact force as a parameter of the time and mass scale factor, respectively.
In explicit analyses, simulation time can be reduced if the total time to be simulated is reduced, or the stable time increment is increased. Preparation of papers for aiaa technical conferences citeseerx. Abaqus standard the nonlinear implicit solver simuleon. Pdf highperformance abaqus simulations in soil mechanics.
With this training course you will learn practical skills and best practices for performing dynamic and quasi static analyses with abaqus explicit including general contact, mass scaling, adaptive meshing, output filtering, material failure, and more. Quasistatic versus dynamic explicit scheme for the modeling. Quasistatic analysis of hip cement spacers sciencedirect. How does the mass scaling reduce the computational cost during. Failure of notched laminates under outofplane bending. Mass scaling is often used in abaqus explicit for computational efficiency in quasi static analyses and in some dynamic analyses that contain a few very small elements that control the stable time increment. The analysis in both abaqus standard and abaqus explicit can also be adiabatic. Abaqus uses a traditional implicit integration scheme to solve fea and uses an explicit integration scheme to solve highly nonlinear transient dynamic and quasi static analyses. This is very helpful when performing quasi static analysis via explicit fea. You can take advantage of rescales scalex platform and its simple workflow to run complex and large abaqus models in.
Each method is recommended for specific types of nonlinear dynamic behavior. Quasi static analysis in abaqus explicit 2 hours both interactive ia and keywords kw versions of the. For quasi static applications, the default maximum increment is the time period of. Three point bending analysis of a mobile phone using. When a mass scaling factor is applied, the mass of the elements with a time increment below a certain value are scaled. This article is aimed to explain the differences and assumptions of each term. However, using explicit procedure to a quasistatic analysis requires some. By adding a mass to these critical elements, the calculation time is decreased. Model parameter sensitivity and benchmarking of the explicit.
The rolling process reduces the thickness of the plate by 42% in a single rolling pass. These technical terms are usually a bit confusing for beginners and occasional users. Abaqus standard, a robust implicit solver to perform highly accurate static and lowspeed dynamic events. Increased load rates reduce the time scale of the simulation. In this analysis, abaqus uses automatic time incrementation method. Several abaqus builtin features enable a wide range of simulating such problems. Mass scaling is often used in abaqus explicit for computational efficiency in quasi static analyses and in some dynamic analyses that contain a few very small. Mass scaling increases the size of the stable time. The analyst must take care when implementing mass scaling and defining loading rates o remove or limit the influence of inertial and damping forces on a systems quasi static response. It increases the size of the stable time increment and so, fewer increments are needed to complete the job. Mass scaling parameter of simulation, limits ability as a predictive tool mass scaling strongly suggested to reduce computation times maximum load percent deviation from experiments. If it is a true dynamic problem where the inertial effects are important, you may not want to use the mass scaling at all.
Quasi static analysis the quasi static analysis approach described in abaqus explicit users manual7 requires that the dynamic effects induced by the applied load are small. Sep 18, 2017 abaqus standard solver uses three different approaches to solve implicit dynamic problems. In a nonlinear analysis abaqus automatically chooses appropriate load increments and convergence tolerances and continually adjusts them during the analysis to ensure that an accurate solution is obtained efficiently. Abaqus technology brief automobile roof crush analysis with.
You can read about it in the abaqus user manual 11. Mass scaling for quasi static analyses is usually performed on the entire. Moreover, due to the quasistatic nature of structural response in fire, the majority. Use scaling for quasi static analyses in abaqus explicit.
Quasistatic versus dynamic explicit scheme for the. Model 10 % 020 plies 30 % 020 plies 50 % 020 plies 20 elements mass scaling 10. Feb 10, 20 analysis then the time increment which abaqus calculates from an element by. For complex problems abaqus can be extended via user subroutines. Comparison of abaqus results with quasi static uniaxial test data fig 2. You can take advantage of rescales scalex platform and its simple workflow to run complex and large abaqus models in batch mode. See implicit dynamic analysis using direct integration, section 6. So can i perform quasi static analysis for the same model using dynamic. In the edit step dialog box, display the mass scaling tabbed page.
Set this parameter equal to the factor that is used to scale the time increment computed by abaqus explicit. For quasistatic applications, the default maximum increment is the time per. It was concluded that this type of analysis is effective to model web crippling failure in terms of loaddisplacement curves and failure modes. Time scaling, mass scaling and damping are common approaches to assist in artificially reducing the computational time but previous articles provide little insight into how to apply these. While the implicit solver in abaqus standard would seem li. Mass scaling massachusetts institute of technology.
How does the mass scaling reduce the computational cost. Abaqus users mass scaling is keie mass scaling and quasi static analysis. Is this a dynamic job or is this is a quasi static simulation. Very complex contact conditions very large deformations mesh distortion possible applications. Increased load rates and mass scaling achieve the same effect. The quasi static analysis approach described in abaqus explicit users manual7.
The test is simulated in abaqus with a 18th symmetry model and a quasi static solution procedure. The timestep is adjusted depending on the behavior of the newton iteration and the accuracy of the time integration. As with many quasistatic processes, the roof crush resis tance test can be. Quasistatic analysis of end plate beamtocolumn connections.
This option is used to provide direct integration of a dynamic stressdisplacement response in abaqus standard analyses and is generally used for nonlinear cases. Abaqus finite element mesh, undeformed top and deformed bottom for solid elastomers, a reasonable assumption can be. For example, the quasi static method works well in problems with severe damping. Mass scaling will be used to reduce the solution time for analysis. Quasi static simulations using explicit dynamics loading rates energy balance in quasi static analyses mass scaling viscous pressure summary workshop 2.
Other approaches could also involve mass scaling, however, this approa. Static, quasistatic and dynamic lessons for civil lessons. Introduction quasi static simulations using explicit dynamics loading rates energy balance in quasi static analyses mass scaling. Bulk viscosity parameter in abaqus explicit finite element. Rust and schweizerhof2 investigated quasi static limit load analysis of structures.
Failure of notched laminates under outofplane bending phase vii. Quasistatic abaqusexplicit analyses brian baillargeon, ramesh marrey, randy grishaber 1, and david b. Abaqus standard s4b cylinder head boltup benchmark is mildly nonlinear static analysis with 5,000,000 degrees of freedom dof and 5 iterations, and abaqus explicit e6 concentric spheres benchmark has. Apr 26, 2008 the first simulation uses the classical implicit quasi static algorithm, the second one uses an explicit scheme without mass scaling with the actual kinematic conditions of the process. Quasistatic simulations using explicit dynamics how much can i increase the load rate or scale the mass.
Incrementation you can control the time incrementation in a quasi static analysis directly, or it can be controlled automatically by abaqus standard. Mar 03, 2021 like mass scaling technique, the mass gravity scaling mgs technique can be applied to the entire model or at a certain part of the model. One general means of evaluating whether or not an explicit simulation is producing an appropriate quasi static solution relies on studying the various energies of the. Quasi static simulations using explicit dynamics energy balance example. In abaqus manual it has been mentioned that the ratio of kinetic to internal energy should be less than 10% for an acceptable solution. Technical white paper hp workstations and simulia abaqus. It is concluded that, all tests carried out with a speed of 0. Workshop 2 impact of a dodge caravan bumper against a rigid barrier. It is used to perform a dynamic stressdisplacement analysis using explicit integration in abaqus explicit. If it is the former, then try decreasing time period without excess mass scaling. For quasi static simulations incorporating rateindependent material behavior, the natural time scale is generally not important. Quasi static analysis in abaqus explicit 2 hours both interactive ia and keywords kw versions of the workshop are provided. Utilize cosimulation perform multiple cosimulations through in the same analysis and combine different behaviours. Bulk viscosity parameter in abaqus explicit finite.
Several extensions for soil mechanics purposes are discussed and corresponding case studies are presented. In the picture below, the time increment of the explicit analysis for the 4 different simulations is shown. You can configure general analysis procedures to analyze linear or nonlinear response. This parameter can be used to scale the default global time estimate, and it can be used in conjunction with the element by element and fixed time incrementation.
You can perform static as well as dynamic analysis see both abaqus standard and abaqus explicit. Simulating nonlinear deformations of solar sail membranes. To achieve an economical solution, it is often useful to reduce the time period of the analysis or to increase the mass of the model artificially mass scaling. Note that the two scaling strategies yield almost equal results for. Quasi static analysis in abaqusfea, part 02 mass scaling. This documentation and the software described in this documentation are subject to change. Introduction to abaqusstandard and abaqusexplicit dassault. Assume that for a quasi static analysis a mass scaling factor of 50 is applied to all the elements in the model. Speeding up quasistatic analysis in abaqusexplicit 1. Quasistatic contact mechanics problem type of solver.
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