This workshop involves simulating quasi static rolling of a plate using abaqus explicit. Quasi static simulations using explicit dynamics loading rates energy balance in quasi static analyses mass scaling viscous pressure summary workshop 2. The degree of discretization varied widely, with the inplane element sizes spanning an order of magnitude from 0. Load rate must be cautiously selected in order to limit the inertial effects. In quasi static loading, the fundamental assumption is that the loading is applied so slowly very low frequency when compared to that of the structure that basically the structure deforms in a static manner. Abaqussoftware inherentlycomplex, anyparticular situation. Simulating nonlinear deformations of solar sail membranes using. The fuselage skin joints studied are test cases from the aforementioned maaximus project. Mass scaling allows you to model processes in their natural time scale when considering. Abaqus standard the nonlinear implicit solver simuleon. In the picture below, the time increment of the explicit analysis for the 4 different simulations is shown. I am using the general contact algorithm with the default frictionless properties.
Key parameters are load rate, mass scaling, contactfriction, residual stresses, imperfections. However, adaptive meshing cannot occur across material boundaries. Jul 09, 2015 basic fundamentals of linear static analysis in abaqus solver is explained in crisp and practical way. By adding a mass to these critical elements, the calculation time is decreased. Used extensively in sheet forming to solve quasi static problems beginning to use explicit method to solve rubber quasi static problems syntax very similar to abaqus standard learn about time scaling and mass scaling techniques. Mass scaling will be used to reduce the solution time for analysis. Firstly we will define the main features, advantages and examples of use of both solvers. When a mass scaling factor is applied, the mass of the elements with a time increment below a certain value are scaled. Dynamic and static analysis of various components using. Feb 06, 2016 quasi static analysis is a useful tool for studying systems which undergo very large deformations. During the quasi static process, the ratio of kinetic energy to strain energy is observed to determine mass scaling parameters that measure the precision of analysis. As a preliminary analysis perform free vibration analysis to obtain 30 vibration modes and their natural frequencies.
In abaqus manual it has been mentioned that the ratio of kinetic to internal energy should be less than 10% for an acceptable solution. 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. Examples of such cases may include the addition of mass to just a few small elements in a noncritical area or quasi static simulations where the velocity is low and the kinetic energy is very small relative to the peak internal energy. Main abaqus analysis users manual, volume 1, version 6. I have read a few papers, especially the ones that have been written on sheet metal forming and they quote the same. Printed abaqusanalysis users manual volume abaqusversion 6.
In the second part, we will show how to correctly implement a quasi static analysis with abaqus explicit. How does the mass scaling reduce the computational cost. Abaqus example problems manual vol1 buckling youngs modulus. No mass scaling was applied and the quasistatic nature of the solution was verified by a negligible ratio of kinetictointernal energy. 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. This part1 video takes you through, how any given static fe problem is solved by abaqus. Lesson 8 quasi static analysis in abaqusexplicit workshop 8 quasi static analysis optional lesson 9 combining abaqusstandard and abaquse xplicit. Used extensively in sheet forming to solve quasistatic problems. The key theoretical aspects of an explicit solver are presented, together with the numerical challenges faced when applied to solving quasistatic problems. Simulation of metal material quasistatic tensile test. Quick fundamentals abaqus linear static analysis fe.
While the implicit solver in abaqusstandard would seem like the obvious choice due to the. Incrementation you can control the time incrementation in a quasi static analysis directly, or it can be controlled automatically by abaqus standard. To do a quasi static analysis you need a notion of the basic. I was trying to run a displacement controlled quasi static analysis on abaqus, but i see an option in the general step only for varying the amplitude instead of the load being ramp or. The illustrative example is a sheet metal forming simulation, which requires importing between abaqusexplicit and abaqusstandard to perform the forming and springback analyses efficiently. Quasi static simulations using explicit dynamics energy balance example. A smooth contact force, as expected for the quasistatic case, is obtained for t 20. In this analysis a relatively stiff part elasticplastic comes into contact with a relatively flexible part hyperelastic. 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.
During the quasistatic process, the ratio of kinetic energy to strain energy is observed to determine mass scaling parameters that measure the precision of analysis. Each of the eight fabric plies was individually meshed with continuum shell elements sc8r. Contact information is listed in the front of each abaqus manual. I am running a large quasistatic structural analysis in abaqus explicit. Quasi static analysis in abaqus explicit 2 hours both interactive ia and keywords kw versions of the. Mass scaling is often used in abaqusexplicit for computational efficiency in quasistatic analyses and in some dynamic analyses that contain a few very small. Using abaqusexplicit to solve quasistatic problems is presented in chapter, quasistatic analysis with abaqusexplicit. Tape spring hinge in folding and unfolding processes with large nonlinearity is firstly simulated using quasistatic analysis technique. I am running a large quasi static structural analysis in abaqus explicit. Oct 30, 2012 all the results are in good agreement with the quasi static analysis results obtained with abaqus standard. Adaptive meshing is not recommended for hyperelastic or hyperfoam. Figure 2 shows the contact force as a parameter of the time and mass scale factor, respectively. Quasistatic analysis is a useful tool for studying systems which undergo very large deformations. Analysis page analysis page is devoted to setting up analyses user profile macro menus user profiles add macro menu pages with tools specific to that solver abaqus step manager, contact manager, component browser ansys contact wizard, component manager, etc.
Adaptive meshing can be used with all material models with the exception of the brittle cracking model. Abaqus example problems manual vol1 buckling youngs. You must ensure that the abaqus explicit analysis generates low ratios of kinetic energy to internal energy 1% or less. Quick fundamentals abaqus linear static analysis fe model. In practical terms this requirement often translates into avoiding the use of mass scaling in the model. How does the mass scaling reduce the computational cost during. In either case the kinetic energy should be monitored to ensure that the ratio of kinetic energy to internal energy does not get too largetypically less than 10%. Quasi static analysis with abaqus explicit analogy for explicit dynamics. It is generally not possible to achieve this in early stages of the. Quasistatic analysis and multiobjective optimization for. Crack propagation analysis massachusetts institute of. The simulation data is compared with the quasistatic tensile test data of a new kind of aluminum and the verification of accuracy is based on numerical fitting method.
This is a document for implement peoples in fields of computational engineering. For more information on quasistatic analysis in abaqusstandard, see quasistatic analysis. Furthermore, assume that even after being scaled by a factor of 50, a few extremely small or poorly shaped elements are causing the stable time increment to be less than a desired minimum. Introduction to abaqusstandard and abaqusexplicit dassault.
Dynamic and static analysis of various components using abaqus and matlab 1. The key theoretical aspects of an explicit solver are presented, together with the numerical challenges faced when applied to solving quasi static problems. Asymmetrically loaded truss concept of symmetry breaking poissons ratio 0. The analysis runs to completion without any issues.
Mar 14, 2016 with the exception of four teams, all other teams used explicit time integration. Static stressdisplacement analyses static and quasistatic. Fixed mass scaling is used to scale the originally defined element masses that are assembled into the global nodal mass matrix. Note that the two scaling strategies yield almost equal results for. For a linear static analysis or a nr scheme choose. Assume that for a quasi static analysis a mass scaling factor of 50 is applied to all the elements in the model. This part1 video takes you through, how any given static fe. This allows the solution to proceed without iterations, and without the requirement of tangent stiffness matrices to be formed abaqus analysis users manual.
The quasistatic analysis approach described in abaqusexplicit users manual7. In most cases experimental andor theoretical data are available in quasistatic settings. The time increment in an explicit analysis is calculated from an characteristic dimension of. Adaptive meshing is supported for all stepdependent features contact, mass scaling, etc. This documentation and the software described in this documentation are subject to change. Use the explicit dynamics method effectively, including the application of general contact, mass scaling, and adaptive remeshing. This is achieved by increasing the density of materials artificially in the analysis while keeping the loading rate realistic. While the implicit solver in abaqus standard would seem like the obvious choice due to the. Quasi static analysis is a useful tool for studying systems which undergo very large deformations.
Quasistatic fe models with explicit integration are proposed to study web crippling. The dominant response of a quasistatic analysis will be the first structural mode. Then you obtain a quasistatic loading scenario with low computational cost. Analysis approach the geometry of the plate was created in abaqus cae and is shown in figure 3. In the end, its up to the judgement of the analyst to gage the affect of mass scaling. Modelling bearing failure in countersunk composite joints.
In a quasistatic analysis it is expedient to reduce the computational cost by either speeding up the simulation or by scaling the mass. For analyses using variable mass scaling, the total mass added to achieve a. Elastic, isotropic material properties were used for the bolt and nut sections titanium. Numerical simulations of quasistatic and rockfall impact. In most cases experimental andor theoretical data are available in quasi static settings.
Abaqus has two different solvers available for structural analyses. All the results are in good agreement with the quasistatic analysis results obtained with abaqusstandard. Basic fundamentals of linear static analysis in abaqus solver is explained in crisp and practical way. You must ensure that the abaqusexplicit analysis generates low ratios of kinetic energy to internal energy 1% or less. The explicit codes do not require the assembly of the global stiffness matrix, and the global equilibrium is not checked. In this paper, we simulate the process of a metal material quasistatic tensile test based on abaqus to discuss the accuracy of simulation data with experimental data. Simulating nonlinear deformations of solar sail membranes. Abaqus users mass scaling is keie mass scaling and quasi static analysis. Fixed mass scaling is performed at the beginning of the step for which it is specified. Abaqus online support system the abaqus online support system aoss has a knowledge database of abaqus answers. I used the mass scaling option to help increase the computational efficiency because without mass scaling, my simulation is taking days to run. Abaqus users mass scaling is keie abaqusstandard and abaquse xplicit. Mass scaling, commonly used to make quasistatic analyses run more efficiently, was applied according to the abaqus user manual chapter 11.
All the results are in good agreement with the quasistatic analysis results. Incrementation you can control the time incrementation in a quasistatic analysis directly, or it can be controlled automatically by abaqusstandard. The results of the largest mass scaling case show pronounced dynamic effects. Jul 18, 2019 tape spring hinge in folding and unfolding processes with large nonlinearity is firstly simulated using quasi static analysis technique. It isnt true where the dynamic and static responses are different, like a cantilever beam excited in the second mode, for example. With the exception of four teams, all other teams used explicit time integration. The explicit integration scheme in abaqusexplicit requires nodal mass or. Abaqus example problems manual vol1 free ebook download as pdf file.
Quasistatic bearing tests on singlebolt and threebolt countersunk composite joints, carried out according to astm d5961d5961m, are the subject of this paper. The rolling process reduces the thickness of the plate by 42% in a single rolling pass. Assume that for a quasi static analysis a mass scaling factor of 50 is applied to all the. Effects of mass scaling hi all, im currently working using abaqus explicit to simulate a needle moving at 0. The kinetic energy of the deforming material should not exceed a small fraction of its internal energy throughout the majority of a quasistatic analysis. In the second part, we will show how to correctly implement a quasistatic analysis with abaqusexplicit. One general means of evaluating whether or not an explicit simulation is producing an appropriate quasistatic solution relies on studying the various energies of the. Explicit dynamic formulation to demonstrate compliance. This concept, which is called mass scaling, reduces the ratio of the event time to.
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