Contact stiffness ansys workbench. This may affect the accuracy of the results.

Contact stiffness ansys workbench. I have tried to do it this way but half way or so through the analysis Ansys mechanical stops outputting the stiffness values to If you determine that a spring exists with an incorrectly defined nonlinear stiffness, the force-deflection curve may be incorrectly defined as a result of the tabular input for nonlinear stiffness for one or more spring objects. 001 usually doesn’t by much convergence The Contact Step Control condition enables you to activate or deactivate specific contact regions on a load-step basis during your analysis. Both of these are penalty-based contact formulations: FNormal = kNormalxPenetration The finite contact Force, F n, is a concept of contact stiffness, k Normal. Change Bonded to Frictional in the Contact between the Glass face and the Rigid mold form. Normal and tangential stiffness values are applied and the contact pair is set to bonded An interference fit is a commonly used technique in mechanical design where one part is installed into another in a way that the frictional force between the Jun 5, 2023 · Thus, if the time step is cut in half, the contact stiffness increases by a factor of 4. MPC prevents artificial stiffness when gaps exist between curved surfaces (another alternative is to use fixed Joints). ). Use to set the stiffness coefficient type: Factor, Constant, Considering Contact Area, d-F Spline, or d-P Spline. 9. Use the questions below to assist you in determining if you need to change any of the default settings To enable flexibility for the user in modeling contact, LS-DYNA presents a number of contact types and a number of parameters that control various aspects of the contact treatment. 7. The higher the contact stiffness, the lower the penetration, x p, as Apr 1, 2021 · When performing structural simulation of large assemblies in Ansys, using non-linear surface to surface contact, we often encounter stability and convergence difficulties, long simulation times and indeed on occasions, failure to achieve a solution. You need to define the source face of the gasket in the Gasket Mesh Control to define the gasket material orientation. Sep 22, 2014 · A good practice would be to manually specify the contact stiffness factor for all contact pairs. 2 seems reasonable. Note that very high stiffness terms introduce high frequencies into the system and may penalize the solution time when using the Ansys Rigid Dynamics solver. Oct 10, 2012 · Reducing the contact stiffness can help with contact convergence for a lot of problems. There seems to be something that I am doing wrong as none of my contacts seem to work (althought these problems I am working on are large displacement). By setting the Stiffness Behavior as Gasket. If the Stiffness Behavior property of a geometry is set to Rigid, you must set the Definition property to Asymmetric. Mar 2, 2022 · This video demonstrates how to apply geometrical contacts in ANSYS Workbench Mechanical. This condition is similar to the Element Birth and Death condition that activates/deactivates element status for a specific load step. See Stiffness Coefficient and Exponent of Penetration in the Motion Preprocessor User Guide for more information. A description of the contact parameters is then presented. Jun 6, 2022 · Here is a sample code for changing the contact siffness factor from 0. See the Reviewing the Results section of the Contact Technology Guide for additional information. Add a Contact Tool and Generate Initial Contact Status, you find there is a small gap. 1 but I get a strange behavior so I want to try whether the factor FKT affects my simulation. Bearings are a critical support for Rotordynamics analyses and as such, a good bearing design is essential to ensure stability of machinery parts under high speed rotations. May 19, 2015 · When a Contact Tool is inserted under the Connections object, it includes a default object, Initial Information. The stiffness is found by taking the nodal mass divided by the square of the time step size with a scale factor to ensure stability. It also enables you to specify the Normal Stiffness for a specific load step. This training manual provides an introduction to contact mechanics as implemented in ANSYS 13. Creation of a Bonded Contact Pair Between Surface Body Faces If surface bodies are created on the midplane of the thin solids that they Aug 5, 2018 · Commands inserted into this file will be executed just prior to the ANSYS SOLVE command. g. com Jun 4, 2015 · For a bonded contact, which is the default for models opened in Ansys Workbench Mechanical, the contacts are modeled using elements TARGE170 and CONTA174. Oct 19, 2023 · Contact types and behaviours are one of the most challanging issues in finite element solutions. Sep 13, 2023 · The tangential contact stiffness will be updated at each iteration based on the current contact pressure, coefficient of friction (MU), and allowable slip (SLTO). Damping Coefficient and Boundary Penetration Damping Coefficient is a part of the damping force which represents a Coulomb damping applied The underlying technology is using penalty-based formulations. when i run the model in transient analysis system it gives me the following message: One or more MPC contact regions or remote boundary conditions may have conflicts with other applied boundary conditions or other contact or symmetry regions. Dec 18, 2023 · I'm doing fiber push-out simulations and took the data from an experiment. Apr 13, 2023 · All Categories Structures - Structural & Thermal How to provide a normal and tangential stiffness to an elastic foundation in Workbench Mechanical? Using the Normal Stiffness property, you can manually increase the stiffness associated with a contact pair. Note that the change in the stiffness factor is linearly ramped over the load step. proprietary information. This may affect the accuracy of the results. Longitudinal springs generate a force that displaces along the axis. Contact for Additional Ansys Mechanical and/or Elastic Creation Support Finally, we hope that you can make productive use of our Elastic Creation/Support article, and varying supportive computations for your Ansys Mechanical models. Jul 30, 2018 · peteroznewman Subscriber Hello Jon, ANSYS provides default values that are sometimes what you want, but in this case, that default choice is not what you want. 3 (Penalty Method). Similar to a spring, a bearing has the structural characteristics of longitudinal stiffness and Jun 21, 2022 · Hi all. 01~10区间内的数字定义接触刚度系数。注意，这个系数不是真实的接触刚度，而是刚度系数，这个系数乘以程序计算出的接触刚度才是真实的接触刚度值。 Ansys, Inc. By setting the Stiffness Behavior as Flexible. Mobile and reference is how ANSYS workbench defines the two nodes it will create to connect the spring to. 5. Under the Geometry Selection method, the Contact Tool can be scoped to any geometry on the model. Additionally, in the Refine stage, you can optionally select a Preload type. One is on the shaft. This feature is useful if a mechanism has only rigid body motion or, if in an assembly, only some of the parts experience most of the strains. This may reduce Select a Longitudinal spring type. The higher the contact stiffness, the lower the penetration, x p, as May 2, 2019 · Requirements of Contact Formulation Numerically, contact is enforced by following three rules: ‐ No penetration between the two bodies ‐ Balance between the applied and the contact forces in case of static problems. As a result, normal contact stiffness can be an important parameter if nonlinear convergence issues arise. Active UNIT system in Workbench when this object was created: Metric (mm, t, N, s, mV, mA) Generate an elastic foundation in normal and both tangent directions May 25, 2023 · Setting a lower contact normal stiffness factor, such as 0. How to add contact stiffness in LS-Dyna Workbench like in LS-Dyna Prepost? SFS and SFM 19. You may need to scale the force unit in the model. 0. . If you want to suppress motion in one direction entirely, it is more efficient to use Joint DOF Zero Value Conventions instead of a very high stiffness. Contact Results If your model contains Contact Regions, you can define the contact results listed below under the Solution object by inserting a Contact Tool . This is accomplished by using an APDL Commands object to generate CONTA174 contact elements on the faces along with matching TARGE170 elements. 4 that explains a lot about Contact Stiffness. The thermal conductivity and stiffness of the contact elements are calculated by Ansys based on the properties of the two bodies. Sep 5, 2024 · Contacts Overview Contact modeling in Ansys Mechanical is a critical aspect of simulating how different parts of a structure interact under various conditions. For more information, or to request engineering expertise for a particular use-case scenario surrounding creation of elastic support with normal and/or tangential The resulting contact stiffness is independent of the material constants and is well suited for treating contact between bodies of dissimilar materials. So again, the contact stiffness is proportional to 1/ (time step)^2. The Considering Contact Area option is recommended when you need to increase contact stiffness in proportion to the increase in the contact area. Enter the spring Length, defined as the distance between the center of the two selected faces or between the center of the selected face and a point. It can be accessed under the Advanced contact settings and can be entered as a numerical value. However, it can also lead to ill-conditioning and divergence. You may need to increase the pinball radius. In the case of pair-based contact, the target surface is defined by the 3D target element type Mar 8, 2011 · Hello, I'm currently working on ANSYS Workbench, and I'm looking for a tool to calculate the axial stiffness of a part. Under the Worksheet method, the Contact Tool is scoped to one or more contact regions. 01 is good starting point if minor penetration is acceptable Check penetration values in post-processing Less than 0. The available behavior options can be accessed from within the Mechanical tree under the details of the geometry body, as shown in the image below. Application To add a bushing: CONTA174 Element Description CONTA174 is used to represent contact and sliding between 3D target surfaces and a deformable surface defined by this element. Stiffness (FKN) Stiffness affects convergence, penetration, hot-spots I rarely use the default value FKN=1 FKN controls spring stiffness – Penalty and Augmented Lagrange Method FKN = 0. We can define these stiffness factors easily in ANSYS Mechanical in the details view for each contact region. Apr 5, 2023 · What is cause of following warning message and how to overcome the same: The maximum contact stiffness is too big. 2 during load step 1 and back to 0. How do I scale the force unit. This article examines a setup to employ with bonded contact pairing across a gap between surface body midplanes in large deflection nonlinear analysis. It can be used for both pair-based contact and general contact. recommends you define MP,EX when using TB,EXPE or TB,USER so that the initial contact stiffness is calculated using a realistic value for EX as defined by the MP command rather than a heuristic contact stiffness that is not influenced by the material property. The amount of slip in sticking contact depends on the tangential stiffness. 1 to 0. In this article we will discuss how to use this feature to “stabilize” challengingRead More “Using Contact Stabilization May 23, 2022 · Hi Everyone I need to export a 96*96 stiffness matrix about a gearbox with screws from ANSYS workbench, but I met some problems. When SOFT=2, contact stiffness is calculated in similar fashion to k1 above and can be scaled by SLSFAC and by SFS. For the augmented Lagrangian method and penalty method, normal and tangential contact stiffnesses are required. TAGGED: ansys-workbench, port-refinement, static-structural, stiffness, workbench Jul 13, 2022 · In this article, we will discuss some aspects of ANSYS contact theory and relate those to the contact formulation options. In this video, we discuss a few ways to resolve this problem and demonstrate the use of one such option, Contact Stabilization Damping, in Ansys Mechanical. Please be aware that the contact stiffness depends on the contact settings SOFT=0/1/2. There are several contact-related parameters in LS-DYNA that can be used to modify or, in many cases, improve contact behavior. However, all is not lost! Ansys has several tools which when used in conjunction with various techniques, can help dramatically. If the contact stiffness is too large, the model may oscillate, with contacting surfaces bouncing off each other. Ansys Mechanical offers a wide range of contact options to accurately model these interactions, including bonded, frictional, and no-separation Pure Penalty and Augmented Lagrange Contact Formulation For nonlinear solid body contact of faces, Pure Penalty or Augmented Lagrange formulations can be used. This setting is ideal for shell-solid, shell-shell, and beam-shell contacts. In this case, you need to define a Gasket Mesh Control in the mesh folder. Using the Normal Stiffness property, you can manually increase the stiffness associated with a contact pair. The amount of penetration between contact and target surfaces depends on the normal stiffness. // INTERESTED IN MORE? 4. It can be specified either through the coefficient of friction (MU) for isotropic or orthotropic friction models or as user defined friction properties. One is on the housing. The Ansys Explicit Dynamics solver does not support tabular input (and therefore nonlinear stiffness behavior). In this case, a Gasket Mesh Control will be added as a child of the gasket body in the model tree. Control normal contact stiffness using the Normal Stiffness property of the Compression Only Support object. 1. In this article, we will discuss how to utilize Contact Trackers in the Solution Information branch to diagnose convergence issues and to determine if the contact leads to a Apr 10, 2007 · I have worked with contacts (mostly small displacement) in the classic environment and have recently moved to WB. In Mechanical contact pairs are color coded as shown here. Regards, Peter October 8, 2018 at 7:47 pm May 1, 2008 · i just took a look in the ansys help file for workbench and found some good guidelines: Simulation Help -> Troubleshooting -> Problem Situations -> The Solver Engine was Unable to Converge Feb 22, 2023 · Ansys Employee Hi javat33489, Contact normal stiffness affects both accuracy and convergence behavior. Automatic Property Specification Note the Description on what is Contact Stiffness?How contact Stiffness affect penetration?How to alter contact Stiffness in Ansys?Guide to choose the right Contact Jun 4, 2020 · In this posting, we’ll cover a contact convergence problem in Ansys Mechanical, including steps to identify this problem and solve it. Download today → https://bit. The contact stiffness is not affected by the time step size, when SOFT=0 (*CONTACT, Optional Card A). For additional information, see the Determining Contact Stiffness and Allowable Penetration, specifically Using FKT and SLTO, section of the Mechanical APDL Contact Technology Guide (Surface-to-Surface Contact). You can change the Contact Stiffness to get rid of that warning. Bearings in ANSYS are COMBI214 springs. Ansys Workbench offers a powerful utility—the Contact Tool—for both diagnosing contact setup and Jun 28, 2019 · 1) ANSYS Help has a Chapter in the Mechanical APDL, Contact Technology Guide, Chapter 3. 01 often helps convergence, except where press-fit is being modeled. It is zero by default. The gasket D. This keyword is created if the contact is specified using Body Interactions and the geometry contains line bodies. Type Choosing the appropriate contact type depends on the type of problem you are trying to solve. Jul 11, 2018 · If finite elements can be connected only in nodes how it is related to the bonded contact ? 2) Is bonded contact adding any fake stiffness to the element ? Meaning is there any difference if I connect two plates by making one part and meshing together or connecting two separate bodys by bonded contact ? 3) Question about info from help file. We […] Apr 29, 2014 · I want to assign an absolute stiffness to the contact elements between the outer surface of inner cylinder and inner surface of outer cylinder in Ansys. 3. how can I solve the problem? 3. Feb 25, 2021 · The soft option will change the way the contact stiffness is calculated and this changes the contact stiffness. Aug 9, 2019 · Hello guys, I am trying to attach the spring between two solid bodies . For a bearing the locations should nominally be coincident. The Report Preview feature does not display table entries from the nonlinear joint stiffness matrix. According to the ansys manual, The program automatically defines a default tangential contact stiffness that The Ansys Rigid Dynamics Solver does support the combination of Constant and Tabular data entries. Jun 23, 2021 · All Channels General Mechanical The maximum contact stiffness is too big. It is not to be distributed to others. Please create a Workbench Project Archive and attach that after you post your reply. Mar 14, 2025 · Introduction All geometry bodies have an associated Stiffness Behavior property in Ansys Mechanical that you can modify for an analysis. ly/32eEcuR // QUESTIONS ABOUT THIS VIDEO OR USING ANSYS? Get help from Ansys experts and peers through the Ansys Learning Forum. It is a purely linear way to connect contacting bodies. The maximum contact stiffness is too big. Fortunately, Ansys Mechanical has a set of tools that help diagnose the cause of divergence. These commands may supersede command settings set by Workbench. Jul 17, 2024 · Contact calculations in structural mechanics: when do I have to use which contact stiffness? Read about this using the example of an electrical connector. If modeling the ability of bodies to separate or open slightly is important and/or obtaining the stresses very near a contact interface is important, consider using one of the nonlinear contact types (Frictionless, Rough, Frictional), which can model gaps and more accurately model the true area May 1, 2015 · Abstract The elastic contact problem, as implemented in some commercial software such as ANSYS, depends on the user choice of some parameters such as normal contact stiffness, penetration limit and contact algorithms. Particularly, not only defining the correct contact type but also identifying the contact problems is often problematic. *CONTACT_AUTOMATIC_NODES_TO_SURFACE Specifies nodes-to-surface friction or frictionless contacts. 9. what is the reason of the aforementioned warning? 2. You should first try running your contact analysis using the default settings, then change settings only if you encounter difficulties or have special situations in your analysis. Contact Settings When a model is imported into Workbench Mechanical, the default setting of the application is to automatically detect instances where two bodies are in contact and to generate the corresponding Contact Region objects. Enter a Stiffness value. However, the contact stiffness is program-controlled in my simulations, how can i change it? I tried changing it to an absolute value but i Pure Penalty and Augmented Lagrange Contact Formulation For nonlinear solid body contact of faces, Pure Penalty or Augmented Lagrange formulations can be used. You only need damping for harmonic response. A large value of stiffness gives better accuracy and less penetration, but the problem may become more difficult to converge. This object provides the following information from the Worksheet. Jun 10, 2021 · I am doing harmonic piezoelectric analysis in Ansys 2021 workbench, when I make precision mesh for piezoelectric bodies, I get this warning on the solution screen. The Ansys Mechanical Workbench Platform has many settings for contact between surface body (shell) faces. nFor a contact with similar material densities and stiffnesses, soft=0 or 1 should work fine. Contact Surface contact elements in Mechanical can be visualized as a “skin” covering the surfaces of the parts in an assembly. 1 during load step 2. Mar 1, 2018 · Hello I am conducting a modal analysis on Ansys workbench ( for an assembly) and i have the following warning : The maximum contact stiffness is too Body-Body based on what you described. friction, bonding, heat transfer, etc. For SOFT=0: Regards, Bernd March 6, 2024 at 10:50 am Henrik Wittberg Ansys, Inc. The resulting contact stiffness is independent of the material constants and is well suited for treating contact between bodies of dissimilar materials. The Stiffness Behavior property is available for a body, a body group, surface bodies, and 2D models. 1 and coefficient of friction 0. Jun 25, 2025 · Learn how to define, troubleshoot, and optimize contact in Ansys Workbench with this complete guide — from contact types to load extraction and solver tips. 6. Subscriber I would like to access the contact stiffness values used by Ansys mechanical to compute the contact forces for a beam to beam contact problem. The element is applicable to 3D structural and coupled-field contact analyses. Whether it’s load transfer across bolted joints, pressure in gasket interfaces, or friction between sliding parts, properly defined contact behavior is essential. what is the effect on the results? hint: I am working on welded joint under fatigue load using mechanical ansys workbench. Do you think it's an important warning ?"The maximum contact stiffness is too big. For contacts that lead to convergence difficulty, you should try lowering the stiffness. In order to achieve an accurate solution, K and n values for the contact must also be determined depending on the geometry shape and material. Because source and target topologies are perfect mirrors of one another, be careful during nonlinear analyses to make Jul 9, 2021 · For all the contacts (Non-Linear as well as Linear), I see an option of penetration convergence tolerance and also normal stiffness of the contact. Apr 29, 2021 · Hello everybodyI am doing a pure bending test with the contact formulation (Pure Penalty) with FKN = 0. So I setup a simple 2-link This section describes the Details pane properties associated with a Joint object. Apr 12, 2002 · "automated adjustment of initial contact conditions" with almost no success. Ansys Contact Types and Explanations Tags: Ansys, contact, Engineering, formulations Show More A Contact Tool is scoped to a given topology, and there exist two methods for achieving this: the Worksheet method and the Geometry Selection method. Time step can affect contact behavior aside from contact stiffness. It is these elements that define the behavior when parts are in contact (e. At first, I defined some Beam contact as screws and gave them two steps Load and Lock in Analysis Setting. The document describes how to create an elastic foundation in ANSYS Workbench that provides stiffness in both normal and tangential directions on selected faces. They don’t do anything without stiffness. , impact) These are the requirements for any contact formulation that is introduced into the model in order to Jun 13, 2025 · 0 (0) Contact interactions play a pivotal role in ensuring realistic results in structural simulations involving assemblies. To set the Stiffness Behavior in the Mechanical application: 5. ‐ Conservation of momentum in case of dynamic problems (e. A bearing is a two-dimensional elastic element used to confine relative motion and rotation of a rotating machinery part. All the parameter cards are the same as in *CONTACT_AUTOMATIC_SINGLE_SURFACE. Mar 5, 2025 · Introduction When conducting a FEA with contact nonlinearities, often convergence difficulties occur due to said contacts. Thanks. When you define a body's Stiffness Behavior as Rigid, you are telling to the application to not allow the body to deform during the solution process. All geometric entities selected for a contact condition, on either the Contact or the Target side of the contact pair, must have the same setting for the Stiffness Behavior property. Select Free length to define a preload Jan 20, 2025 · Learn effective strategies for resolving interference fits in Ansys Mechanical, focusing on contact algorithms, mesh quality, and solver settings to improve accuracy and stability. Contact Friction Contact friction (TB,FRIC) is a material property used with current-technology contact elements. Jul 13, 2023 · 5 (9) INTRODUCTION Contact stabilization damping is a feature associated with non-linear (frictionless, frictional, and rough) contacts in ANSYS. This behavior only crops up when the default values for contact stiffness factor are utilized. Too low of a stiffness value can cause problems too, but in this case the resulting penetration is still small so a value of 0. I am asking this because sometimes, my solution is unable to Mar 6, 2024 · Bernd Hochholdinger Ansys Employee Dear Henrik, you can find the formulas for the calculation of the penalty contact stiffness in the LS-DYNA Theroy Manual section 29. Contact elements cannot penetrate the target surface, but target elements can penetrate through the contact surfaces. Sep 12, 2018 · What are the general guidelines under which we should start using non-program controlled stiffness?For typical contact problems lets say gear to gear contact / cam to follower contact/ contacts between pin joints of a mechanism, what is the best approach with normal stiffness? Contact Properties: Basic The Basic tab contains general properties related to contact behavior and convergence. Normally I would get this by using a contact result tracker. 19. Sep 15, 2017 · Best Practices for Contact Modeling This presentation contains ANSYS, Inc. I want to know the default values used by the solver for each of these, and for each of the contact. In the following sections, contact types are first discussed with recommendations regarding their application. *CONTACT_AUTOMATIC_GENERAL Specifies friction or frictionless contacts between line bodies (beams). And try setting the “update stiffness” to “each iteratiion” or the aggressive setting. Does anyone have any good solid tips so that my problems will converge better and prevent initial penetration? In particular I am using Ansys Workbench for large 3D assemblies (I'm mad that there are no P-elements but that's a different story) and Ansys Classic mainly for 2D. In this tutorial we explore the way on how we can extract this from Workbench. One caveat is that MPC is the most sensitive contact See full list on featips. I previously try to do it by applying a force on the top, and considering the deplacement (Stiffness = F/Displasment) But I definitly does not work! (my part is more or less a Oct 7, 2018 · Do any of the materials have plasticity or other nonlinear behavior? If so, you may need to use Substeps to take smaller load increments. Jan 6, 2024 · Description In design analysis, you may want to extract the full or sparse stiffness and mass matrix generated in a modal analysis or stiffness matrix generated for steady state analysis in order to verify or utilize it for comparison purposes. Additionally, it discusses the enforcement of compatibility in contact regions, various contact formulations available in Workbench-Mechanical, and provides insights into Numerical Modeling of Contact – Contact Stiffness When defining contact between two bodies or surfaces in Ansys Mechanical, we need to define the contact side and the target side. In this post we explained the details of the contact tool in Ansys to explore the contact status of your FE models. 1 or 0. I'm not able to match the results with the experimental findings as it says the contact stiffness is very high. A high stiffness setting can lead to reduced penetration and an increase in accuracy. It involves defining how surfaces come into contact, whether they touch, slide, or separate. 2) When two bodies make contact, the solver must create an equal and opposite force to prevent penetration, but what direction should that force be applied? Ansys, Inc. It covers essential characteristics of contact surfaces, including their ability to resist interpenetration and transmit forces. It can be affected, if SOFT=1 and it is definitely affected when SOFT=2 is set. Learn the best approaches to avoid excessive contact penetration between the structures in Ansys Mechanical by exploring this knowledge material. Advantages of MPC Contact The MPC Formulation option does not provide stiffness settings. You may need to scale the force Ansys, Inc. This 当选择手动输入接触刚度时，会出现Normal Stiffness factor 这个框框，输入0. okl kd2c36g wljjs zv mjnfxauq 5dv a789 m0dojuq jed 1w7xw