Jump to content

Search the Community

Showing results for tags 'contact'.



More search options

  • Search By Tags

    Type tags separated by commas.
  • Search By Author

Content Type


Forums

  • Altair Support Forum
    • Welcome to Altair Support Forum
    • Installation and Licensing
    • Modeling & Visualisation
    • Solvers & Optimization
    • Multi Body Simulation
    • Conceptual design and Industrial design
    • Model-Based Development
    • Manufacturing Simulation
    • CAE Process Automation
  • Academic Partner Alliance Forum
    • APA - Composites
    • APA - CFD & Thermal
    • APA - Vehicle Dynamics
    • APA - Manufacturing
    • APA - Crash and Safety
    • APA - Noise, Vibration and Harshness
    • APA - System Level Design
    • APA - Structural and Fatigue
    • APA - Marine
    • APA - Optical Design
  • Japanユーザーフォーラム
    • ユーザーフォーラムへようこそ
    • Altair製品の意外な活用例
    • インストールとライセンス
    • モデリング(プリプロセッシング)
    • シミュレーション技術(ソルバー)
    • データ可視化(ポストプロセッシング)
    • モデルベース開発
    • コンセプト設計と工業デザイン
    • 製造シミュレーション
    • CAE プロセスの自動化
    • 学生向け無償版
    • エンタープライズソリューション

Categories

There are no results to display.


Find results in...

Find results that contain...


Date Created

  • Start

    End


Last Updated

  • Start

    End


Filter by number of...

Joined

  • Start

    End


Group


AIM


MSN


Website URL


ICQ


Yahoo


Jabber


Skype


Interests


Organization


Location

Found 111 results

  1. Hi all, I would like to model contact between 2 gears (like image in attached file). I took this illustration in a Altair document dealing with contact problems. But, the author do not mention how to implement this kind of contact in optistruct. Does anyone have any idea/advice on how to do this in optistruct? Thanks for your help. GAYE
  2. Dear all, I'd like to ask you for help regarding specific contact simulation. Please have a look at the sketch below (I know that this particular case can be easily calculated analytically ). There is a L-shape profile (on the right) which is screwed in to a flange on the left. There are two types of connection: Pin connection - pins transmit shearing load (red) Bolted joints which ensure flanges integrity (blue) There is also a contact plane marked in yellow. I have modeled pins explicitly with merged nodes between flanges as shown on the figure below. My question is how to model the contact between blue and dark yellow elements? Ideally it would be kind of no separation contact so both surfaces remain fixed but no shear load is transmitted. I want the pins to carry all shear load and I'm not interested in the bolts assessment. There is a nice presentation about optistruct contact settings - Optistruct Contacts.pdf And even contact type "NOSEP" is described but I can't find it in my v13. Could you please give me any advice? Thank you in advance.
  3. Hello, I’m currently trying to do a contact analysis of a shaft-hub joint-connection in RADIOSS. The model: Both parts are initially in closed contact with each other in a press-fit joint-connection. The shaft is rotating around its axis with very high velocities and eventually the cylindrical hub detaches from the shaft when a critical rotational velocity is reached or due to fatigue. I would like to simulate that detachment process in RADIOSS and have now come across several problems I can’t find a solution to. ------ Here is what I do: 1. After meshing the geometries with solid elements I create a rigid body at one end of the shaft to apply CLOADS or rotational forces to it. 2. I create a contact surface on the outer surface of the hub and apply a PLOAD all around it to simulate the press-fit connection between the hub and the shaft. 3. Properties and materials are defined for both the rigid and solid elements. 4. I create a Contact between hub and shaft and select the shaft-component as the slave and the hub-component as the master. 5. A local coordinate system is placed at the center of the shaft to define the axis of rotation. 6. Next, a rotation should be added to the system, however, that’s when the problems start. - When I try to apply an “initial velocity around an axis” load collector around the shaft axis(local system) I get the error that the wrong reference frame was selected. However, when I select the global system, the error “Direction should be x y or z & right justified” is detected. - When I use an imposed velocity/acceleration, I simply get zero displacements everywhere as if the load collector was not created at all. These errors occur no matter whether the velocity is applied to the rigid or the shaft component itself and with or without a PLOAD collector active or not. -When I applied CLOADs on two sides of the rigid body, thus creating torque, it didn’t work in combination with the applied PLOAD. In another forum entry it was explained that a simultaneous application of multiple loads like that is not possible. Instead they should be applied one after another and in the end the combined effects could be evaluated. However, the results do not show a combined load case like intended. Additionally, the rotation does not continue in one direction only, but bounces back and forth after a while when CLOADS create the torque. ----------------------------------- ----------------------------------- My first question would be whether my intended goal – observing the contact/detachment process between hub and shaft at a critical rotational velocity- is possible to implement in RADIOSS like that or what I would need to adjust to make it work. 2. How can I apply a rotational velocity to the shaft in order to rotate the component in one direction only? 3. Since the hub is supposed to be rotating with the shaft before detaching, what contact is needed to simulate that detachment behavior? I would be happy to send the files to make it easier to understand the model and output since this explanation probably isn’t enough to give a clear answer to all of my problems. Thank you in advance for the support!
  4. Hello, I am modeling contact stress in the patellofemoral joint. I have models that have been meshed and made in Hypermesh and are being exported into a .cdb file to be read and analyzed using ANSYS 14.5. I have created a entity set in Hypermesh of nodes to allow me to use the contact wizard in ANSYS. I have been able to successfully import the model and run my simulation however the models are not initiating contact. I was talking with my PI and he suggested that perhaps the entity set is causing the nodes to lose association with their corresponding nodes. This is preventing contact from occurring. Is this the case? And if so how do I remedy the situation?
  5. Hi, I hope I do not bother anyone with questions to which answers might be obvious to advanced users. Using Hyperworks 11, I'd like to create a simple adhesive contact in Hypermesh between two solid compontents, hex mesh. The tutorial HM-3410: "Creating Area Connectors" only treats 2D-elements and doesn't work the same way for 3D-elements. Could anyone give me a short hint how to "glue" two compontens together, please? I would appreciate it very much. Have a nice day Hampel
  6. I am exploring the use of discrete sphere elements in LS-DYNA, and I was wondering if any guidance regarding output options specific to this element type could be provided. In particular: 1. Is it currently possible to obtain output of the sphere-to-sphere contact forces? 2. Is it possible to obtain output of stresses that develop across each discrete sphere element surface? Thanks very much for any feedback .
  7. Hello everyone, I would like to learn the duty of "clearance" in PCONT card. In Hypermesh help it says: "Prescribed initial gap opening between master and slave, irrespective of the actual distance between the nodes."; but that does not explain anything for me. Could anybody tell me in a detailed way, what happens when i use clearance section in PCONT card for contacts. Thanks in advance.
  8. Is it possible to create contact between two surfaces edges in Optistruct? does it require a special interface type? I tried creating a contact interface with an element set for master and a node set for slave, but it doesn't work. The solver outputs this error: *** ERROR # 1762 *** Incorrect SET type for MSID This video explains how to do what I'm trying to do in the Ansys profile. I would like to know how to do it in Bulk data format. https://www.youtube.com/watch?v=Bx6JFiqeCmM Thanks in advance!
  9. Hello to all, I'm trying to model a wheel that rotates on a plane without slipping, but that can lift off the floor when it's needed. I used the contact command and Poissoin's algorithm, but I wonder if there is another way to do it. Is it necessary to write a subroutine? thank you
  10. Model description: A set of gears Load:Torque Non-linear analysis conditions (NLSTAT) There have contact between the gears (Slide) Problem Description: The ideal result should be that the largest stress is at the root of the tooth, but the analysis result is that the largest stress is at one point of the tooth surface. This maybe stress concentration. Is it a model problem? Or, if not, how to solve the stress concentration problem caused by this analysis. When I look at the results at different times, stress is still relatively uniform even at t=0.9, but stress concentration occurs at t=1.0. Is the load equally divided? The following pictures show the stress results On the left is t=0.9. On the right is t=1.0.
  11. Hello, I have set a Nonlinear quasi static analysis (type NLSTAT) with two consequent load steps (using CNTNLSUB option). In my model two parts are gradually getting in contact (something similar as roller - plane contact), where also friction is taken into account. In the first step a radial force is pushing the roller towards the plane and in the second step additional lateral force is applied. Everything works fine, the results seem meaningful. Now I would like to set a first load step with contact type SLIDE and the second (continuous) load step with friction in contact. Is this possible in Optistruct? Thanks for your help! Best regards, Matej
  12. Hello Sir, I'm working on bullet penetration into steel plate. At first contact works beetwen bullet and plate, but next it doens't work so good (picture 1). Finally, contact again work (picture 2) and I don't know where is a problem. On top of that, the speed of the projectile doesn't decrease (picture 3). Contact settings: Type 7 Istf: 4 Igap: 2 Fric: 0.2 Gapmin: 0.1 Inacti: 6 I tried a lot of contact setting, among others: Type 7 Istf: 4 Igap: 2 Idel: 2 Fpenmax: 0,8 Stmin: 1000 Fric: 0,1 Gapmin: 0,04 Inacti: 6 Iform: 2 but still doesn't work. Thanks for helping me. test21.hm
  13. How to define a contact between two surface of shell elements in Nastran profile? Which card image i should use? I created slave and master elements using contact surface collector . Am doing linear static and normal mode analysis.
  14. Hi all, I'm encountering a problem in a low-velocity impact simulation with a composite plate. As you can see from the image below, at the beginning of the analysis, the impactor literally penetrates the plate but without effective failing of any elements. I experience this problem when I try to simulate the delamination, ply by ply (in my case 16 ply), using very thin shell elements (the thickness of each ply is approximately 0,23 mm). Indeed, after studying the contact problem in LS-DYNA, I figured out that, when very thin shell elements are used, the plate drastically fail when the impactor approaches it. For this reason I had to reduce the SLSFAC from 0.1 to 0.001 in *CONTROL_CONTACT in order to have reasonable results, because the impactor of only 1,5 kg and with an initial velocity of 6,5 m/s destroyed the plate in the very first milliseconds of the simulation without this change. But now, solved one problem (however I'm not really sure about this, maybe someone can explain me better this contact stiffness problem), I have another one I'm using a MAT22 model for the composite and a MAT20 for the impactor (made of steel). To simulate the delamination I chose the *CONTACT_AUTOMATIC_SURFACE_TO_SURFACE_TIEBREAK with 15 delamination model in between, penalty contact SOFT = 0 (justified by the fact each ply is identical) and OPTION = 8 for the failure criteria (I didn't know if PARAM = CCRIT for this option had to be used, so I left it blank). For the contact between impactor and the plate I chose *CONTACT_AUTOMATIC_SURFACE_TO_SURFACE with SOFT = 2 (because of the different materials and meshes), FS=FD=0,5 and with the impactor being the master and all 16 plies being the slaves. Any suggestions to solve this problem? Thanks in advance for any response. impatto.bmp
  15. Hello, I'm modelling a complex structure in Hypermesh with Nastran profile and I need to connect two components. One is a tube meshed with pshell elements while the other is a solid meshed with psolid. The tube is perpendicular to the solid surface but I cannot have the same mesh for various reasons. In Abaqus I would use a tie constraint between the edge of the tube and the surface of the solid but I can't understand how to do so with Nastran and Hypermesh. I tried to use the cards BSURF, BCONNECT AND BCTABLE but I'm not able to figure out how they works. Any suggestions would be highly appreciated. Thank you! Stefano
  16. Hi, I am doing spur gear to spur gear transmission analysis on motionview (gears have module 1 & teeth of the gears are 28 and 82). I used the rigid to rigid type gear contact and used poisson model with parameters as ,penalty = 1000, COR = 1, Normal transition velocity = 1mm/s to define the contact. I gave uniform rotational speed to the gear with 28 teeth and i requested for the output of rotational speed of the gear with 82 teeth. Theoretically i should be getting output plot to be a straight line with slope 0 & 1.024 rad/s (marker velocity) above x axis (time), but i am getting a curve which is not throughout straight line, plot shows a max peak of 7 rad/s velocity as well. What could be the issue for this?
  17. Hello everybody, I'm a Student and have to do a thesis. The thesis is about a FEA about an large bearing. But I'm a beginner in Hypermesh. Does someboby has some tips for modeling of the isssues "initial bolt prestress", "hertzian stress" and general Information which is important to consider?
  18. Hi everybody. I am designing a rapid attach system for the bucket of a skid steer loader (see picture below), taking inspiration from the commercial systems. In the second picture you can see how this system work: there a contact surface between the bucket and the tach. So there is a contact zone and of sure I should do a non-linear quasi static analysis; however since I would not do a non linear analysis I ask you if there is another way to get a solution. I've already done a non linear analysis but I can't validate the results since this kind of analysis should be quite instable. So I'd like to find another way (with linear analysis) just to compare the results. Thanks in advance for your help Best Regards Stefano
  19. Good morning, I am modeling a rotor composed by three components: shaft, magnet and surrounding fiber. I would like to evaluate the effect of thermal expansion, simulating the contact between the three components. I have some difficulties with contacts (the contact force is not constant, as expected). Differences are quite small, but I would like to ask you if there are any errors in my model or if there are any possibilities to obtain better results (I have already tried with s2s option in contact definition and with expertnl param). Thank you so much for your kindness Enrico
  20. I want to know what this error mean when i used comp in interface definition of contact: ERROR id : 475 ** ERROR SURFACE BUILD FROM SOLIDS PART NON AVAILABLE OPTION /SURF/PART/Surf_ID FOR CREATING SURFACE 6 FROM A PART OF SOLIDS ;
  21. Hello, i am simulating a contact (slide) between a pin and a lug. At the beginning of the motion everything is fine, but at the end the pin is penetrating the lug. The pins displacement is implemented with a constraint. I already tried to change master and slave, but it didn't work. I have no idea what to do next, do someone have some hints maybe? I attached a screenshot of my card settings and the movement of the pin.
  22. Hi All How do we assure a mesh continuity on the border between two spherical parts, one inside the other one, in contact with each other?
  23. Hi all, I am looking for some assistance in impact testing within Radioss. I have been working on the pre-processing part where I have set up the material for the composite using LAW25, and as a result, used P10 as the property card. Also, I have defined type 7 contact between the steel indentor and the composite specimen (the whole components were chosen rather than inidividual nodes). I am finding it difficult to define the output control cards properly. Specifically, the following control cards: ENG_ANIM_DT ENG_OUTP_DT ENG_OUTP_DT ENG_RUN ENG_TFILE How do I determine these values? I believe, the values I am inputting are wrong, and running my simulation seems to take minimum of 45 minutes. . Also, how do I obtain physical data from the simulation, which I can then use to plot parameters with respect to time? Thanks.
  24. Hi, I've previously had help from one of your colleagues with my model for which they suggested I do a Mesh-->Check--> Elements-->Penetration as I had a problem with my slide contact surfaces. I fixed the majority of these penetrations with the auto manager (not all were fixed) and tried to relaunch the calculation. However, now my model does not manage to converge and I don't fully understand why, even after reading up on all of the input fields in the contact menu. Any help would be greatly appreciated (model is attached)! Thanks in advance. 151207_MD_01_A-42.hm
  25. Hello, I would like to calculate a contact between a sphere and flat solid block, pressed together under certain load. I am interested in the contact stress and precise contact area (I would like to compare the results with the analytical solution of Hertzian contact theory). Is it feasible to get the desired results with a non-linear quasi static analysis in Optistruct or shall I do it with Radioss? Additionally, what is the best way to obtain the final nodes in contact or even to fix them together and perform an additional analysis? Thank you for you help, Matej
×
×
  • Create New...