I am suspecting the problem may be caused by the use of nonvector rotational variables. Arbitrary lagrangianeulerian finite element formulations applied to geotechnical problems montaser bakroon, reza daryaei, daniel aubram, frank rackwitz abstract. Ale methods use a generalized formulation and capture the advantages of. Updated lagrangian formulation for incremental general nonlinear analysis. Simulation of end milling on fem using ale formulation. Principle of virtual work in terms of 2nd piolakirchhoff stresses and greenlagrange strains referred to the configuration at time t. Lagrangian formulation, which is based on the concept of material coordinates lagrangian coordinates.
However, its first application to metal cutting was reported by usui et al. When does abaqus use the total lagrangian and when the. Lagrangian formulation was used by most of the researchers, except strenkowski, moon, and athavale 5, 6 that prefer to use the eulerian. Hi everybody, i need to run a blast simulation in abaqus using cel technique. The finite element method for the analysis of nonlinear and.
Escall on lecture 11 17 december, 20 institute of structural engineering method of finite elements ii 1. This additivity states that the equations of motion of part a can not be dependent on. Some models parts tools are described by updated lagrangian formulation, other parts material are described. Bird strike damage analysis in aircraft structures using abaqusexplicit and coupled eulerian lagrangian approach. This paper presents the steps to achieve a fe model of the fsw process in the abaqusexplicit software, using the coupled eulerianlagrangian formulation cel, the johnsoncook constitutive. The tutorial is intended to serve as a quick introduction to the software for the students in professor des mane 4240civl 4240 course at rpi and. Coupled eulerianlagrangian abaqus dassault systemes. Incremental stress and strain decompositions in the updated lagrangian form of the principle of virtual work. However, its first application to metal cutting was.
The lagrangian point of view is used for the mechanical modeling capabilities in abaqus. Total lagrangian explicit dynamics finite element algorithm for. Then he told me something i have always found fascinating. Introduction to lagrangian and hamiltonian mechanics. Some topics can be found in the abaqus manual 14 and others are experience.
For uel, i think the user may choose either formulating in updated or total lagrangian. Examples in lagrangian mechanics bloomington, indiana. Adaptive meshing and distortion control imechanica. The adaptive meshing implementation in abaqusexplicit is very general adaptive meshing is very costeffective in an explicit framework. Just for comparison, lsdyna, another fe software package, does report lagrangian strain. As a result, the deformation process is split into a pure lagrangian phase and a pure eulerian phase combined with a smoothing phase. The arbitrary lagrangian eulerian ale method is an explicit numerical for mulation which has become a standard tool to solve large deformation problems in solid mechanics. The impacting forces are transferred to the lagrangian structure through eulerian lagrangian contact which is based on the penalty contact algorithm. Mechanics is that lagrangian mechanics is introduced in its. The arbitrary lagrangian eulerian ale method is an explicit numerical formulation which has become a standard tool to solve large deformation problems in solid mechanics. Lagranges equations are also used in optimization problems of dynamic systems. The scheme is lagrangian and hamiltonian mechanics. The uncoupled approach has some advantages with respect. Coupled euler lagrangian approach using abaqus explicit.
In this handout, we will discuss a lagrangian finite element formulation for large deformations. Polymer flow in package sealing process a coupled eulerian. In a pure lagrangian formulation each individual node of the computational mesh is permanently connected to the same material point during motion. This expression is written in abaqus theory manual as. First that we should try to express the state of the mechanical system using the minimum representation possible and which re ects the fact that the physics of the problem is coordinateinvariant. This paper presents the steps to achieve a fe model of the fsw process in the abaqus explicit software, using the coupled eulerian lagrangian formulation cel, the johnsoncook constitutive. Airplane structures, composites, bird strike, impact damage, coupled eulerian lagrangian analysis, contact, high lift devices, abaqus explicit. This video is on cel modelling example in abaquscae 6.
It does not attempt to minimize discretization errors in smalldeformation analyses. Application of coupled eulerian lagrangian approach in metal forming simulations numerical simulations of materials forming processes require both powerful computers and advanced software. Abaqus uses the updated lagrangian formulation stress measure abaqus always calculates cauchy true. Eulerian analysis massachusetts institute of technology. The interaction behaviour between the two is modelled by contact definition.
In abaqus program the coupled eulerianlagrangian analysis is restricted. The paperboard however is modeled using the lagrangian description according to common practice at tetra pak. The new coupling of the eulerian domain and lagrangian domain makes new types of analysis capabilities available that may not have been available before, one of them being sloshing in a flexible tank. Coupled euler lagrangian approach using abaqus explicit in the bird strike aircraft damage analysis 1. Adaptive meshing in abaqus explicit is intended to model largedeformation problems. The coupled eulerianlagrangian cel approach in abaqus which provides engineers and scientists with the ability to simulate a class of problems where the interaction between structures and fluids is. Lagrangian mechanics our introduction to quantum mechanics will be based on its correspondence to classical mechanics. Consequently, lagrangian mechanics becomes the centerpiece of the course and provides a continous thread throughout the text. The approach taken is mathematical in nature with a strong focus on the. Eulerianbased finite element formulations or attached to material e.
The main task of the thesis is to evaluate if the recently implemented coupled eulerian lagrangian formulation in abaqus is a proper strategy of modelling the the sealing process. I tried to search its documentation, but didnt find any relevant information. Nonlinear elastic analysis using abaqus 24 2d solid continuum elements plane strain. Before in tro ducing lagrangian mec hanics, lets dev elop some mathematics w e will need. Lagrangian dynamics most of the material presented in this chapter is taken from thornton and marion, chap. Before cel, tank sloshing in abaqus involved modeling the fluid as a deformable mesh within classical lagrangian framework 1. Apr 12, 2016 abaqus explicit arbitrary lagrangian eulerian formulation ale orthogonal cutting of aisi 1045 extended check out more machining tutorials.
Bird strike damage analysis in aircraft structures using. This new modelling technique enables better capturing of fluidlike bird behaviour upon impact in the velocity range at which bird strikes usually occur. Lagrangian mechanics is widely used to solve mechanical problems in physics and when newtons formulation of classical mechanics is not convenient. Arbitrary lagrangian eulerian finite element formulations applied to geotechnical problems montaser bakroon, reza daryaei, daniel aubram, frank rackwitz abstract. Lagrangian and hamiltonian mechanics a short introduction. Example 1 in figure 1 we show a box of mass m sliding down a ramp of mass m. When does abaqus use the total lagrangian and when the updated lagrangian formulation. Adaptive meshing is supported for all stepdependent features.
The lagrangian f orm ulation of mec hanics reading assignmen t. Mar 03, 2017 this video is on cel modelling example in abaquscae 6. The lagrangian formalism when i was in high school, my physics teacher called me down one day after class and said, you look bored, i want to tell you something interesting. Coupled euler lagrangian approach using abaqusexplicit in the bird strike aircraft damage analysis i. In general, the safest method for solving a problem is to use the lagrangian method and then doublecheck things with f ma andor. The impacting forces are transferred to the lagrangian structure through eulerianlagrangian contact which is based on the penalty contact algorithm.
Total and updated lagrangian formulations imechanica. Eulerian elements may not always be 100% full of materialmany may be partially or completely void. Arbitrary lagrangianeulerian finite element formulations applied. Paper open access related content numerical simulation of the. Konkol and balachowski, 2016 used abaqus to compare lagrangian and ale. Abaqus users question about geometric nonlinearity.
Arbitrary lagrangianeulerian finite element formulations. A students guide to lagrangians and hamiltonians a concise but rigorous treatment of variational techniques, focusing primarily on lagrangian and hamiltonian systems, this book is ideal for physics, engineering and mathematics students. Abaqus explicit arbitrary lagrangian eulerian formulation ale. Interaction between structure and water in seismic analyses of nuclear facilities cecilia rydell1, tobias gasch 2, luca facciolo3, daniel eriksson and richard malm4. I dont really know the procedure used in abaqus, but several fe codes prefer a tl approach for. Updated lagrangian formulation for incremental general nonlinear analysis principle of virtual work in terms of 2nd piolakirchhoff stresses and greenlagrange strains referred to the configuration at time t. The tutorial is intended to serve as a quick introduction to the software for the students in professor des mane 4240civl 4240 course at rpi and should, in no way, be deemed as a replacement of the official documentation distributed by the company that sells this software. Theory, implementation, and practice november 9, 2010 springer. Abaqus high level of detail manual design of workpiece and tool, free model. Large displacements assumed in the analysis usually cause convergence problems. How to model eulerian regions in a coupled eulerian lagrangian simulation in abaqus. Readers are referred to abaqus analysis users manual 22. Both methods give exactly the same equations kr mgcos.
It is more suitable for fluid flow problems, which involves a control volume. As a preliminary analysis perform free vibration analysis to obtain 30 vibration modes and their natural frequencies. By contrast, in an eulerian analysis nodes are fixed in space, and material flows through elements that do not deform. Application of an uncoupled aleformulation to confined. Lagrangian elements are always 100% full of a single material, so the material boundary coincides with an element boundary. Chapter 3, elements, describes the element formulations. Total lagrangian formulation where 0 e ij is the linear incremental strain, 0. Coupled euler lagrangian approach using abaqus explicit in. This video shows you how to develop cel simulation model with example enables you to practice and reproduce the. Ivancevic department of aeronautical engineering, faculty of mechanical engineering and naval.
The finite element method for the analysis of nonlinear. At this point it seems to be personal preference, and all academic, whether you use the lagrangian method or the f ma method. There are two main ways of approaching problems that involve the motion of deformable materials the lagrangian way and the eulerian way. The ramp moves without friction on the horizontal plane and is located by coordinate x1. Compared to the classic lagrangian modeling of the bird, the analysis has proven to be more stable, and the results, such as and damage areas, physically more realistic. It gives no new information theres no advantage to it. Pdf application of the coupled eulerianlagrangian cel.
The lagrangian formulation, in contrast, is independent of the coordinates, and the equations of motion for a noncartesian coordinate system can typically be found immediately using it. Application of coupled eulerianlagrangian approach in metal forming simulations numerical simulations of materials forming processes require both powerful computers and advanced software. An important concept is that the equations of motion of classical mechanics can be based on a variational principle. Improving mesh quality increases the stable time increment size, which makes up for the added cost of the adaptive mesh increments. These approaches are distinguished by three important aspects.
The finite element method for the analysis of nonlinear and dynamic systems prof. A benchmark example of a simple tank sloshing problem is included to evaluate the use of different fsi methods. Lagrangian mechanics applies to the dynamics of particles, while fields are described using a lagrangian density. The main improvement has been achieved by replacing the lagrange bird model with the coupled eulerian lagrangian formulation implemented in abaqus. Alebased finite element simulations can alleviate many of the. Abaqus explicit arbitrary lagrangian eulerian formulation ale orthogonal cutting of aisi 1045 extended check out more machining tutorials. Lagrangian formulation thats the energy formulation now onto the lagrangian formulation. Advantages of arbitrary lagrangianeulerian finite element techniques the arbitrary lagrangianeulerian ale is a finite element formulation in which the computational system is not a prior fixed in space e. I will assign similar problems for the next problem set. Its original prescription rested on two principles. An important concept is that the equations of motion of classical mechanics can be. Coupled eulerian lagrange cel analysis with abaqus.
Dzierba sample problems using lagrangian mechanics here are some sample problems. The main task of the thesis is to evaluate if the recently implemented coupled eulerianlagrangian formulation in abaqus is a proper strategy of modelling the the sealing process. For some reason, i am writing a finite element program using the timoshenko beam element and total lagrangian formulation for geometric nonlinear analysis. Although the adaptive meshing techniques and the user interface are similar in abaqus explicit and abaqus standard, the usecases and the level of functionality are different. Learn how to setup a coupled eulerianlagrangian cel model of the moulding process of a polymeric bottle. How to model eulerian regions in a coupled eulerian. In our ellipsis code, the problem domain is represented by an eulerian mesh and an embedded set of lagrangian integration points or particles. The coupled eulerian lagrangian cel approach in abaqus which provides engineers and scientists with the ability to simulate a class of problems where the interaction between structures and fluids is important. Paper open access related content numerical simulation. The abaqus documentation often refers to ale adaptive meshing simply as adaptive meshing. Hyperelastic material analysis using abaqus element,typec3d8rh,elsetone. Hi astlaia2002, it is stated that the elements are formulated in the current configuration using current nodal positions when nlgeom option is specified abaqus standard manual analysis analysis types introduction therefore, the updated lagrangian formulation is used when nlgeom is specified. Visit the simulia resource center for more customer examples.
Abaqus explicit arbitrary lagrangian eulerian formulation. Contrary to the lagrangian formulation, is the eulerian formulation where the mesh is spatially fixed. The purpose of this technique is to avoid mesh problems when performing simulations that involve highextreme deformations. Coupled eulerian lagrange cel analysis with abaqus this analysis techniques combines two mesh approacheslagrangian and eulerianin the same analysis. Advantages of arbitrary lagrangian eulerian finite element techniques the arbitrary lagrangian eulerian ale is a finite element formulation in which the computational system is not a prior fixed in space e. Regional contact information is listed in the front of each abaqus manual. How to model eulerian regions in a coupled eulerianlagrangian simulation in abaqus. A lagrangian integration point finite element method for. Free abaqus tutorials to build and expand your experience on simulia abaqus fea software. An introduction to lagrangian and hamiltonian mechanics. This type of adaptive meshing is often referred to as arbitrary lagrangianeulerian ale analysis. Abaqus coupled eulerian lagrangian cel modelling tutorial. The adaptive meshing technique in abaqus combines the features of pure lagrangian analysis and pure eulerian analysis.
300 1472 1387 826 891 992 107 1228 1279 1505 1076 622 841 1033 947 1147 310 1528 325 1300 623 704 1232 1370 1385 850 604 161 460 639 304 315 952 819 697 1477 372 396 340 558 875 1267 449 1351 189 781 1231 347