http://www.FEA-Forums.com/ FEA Forums » Recent Posts en Fri, 12 Mar 2010 02:54:12 +0000 http://www.FEA-Forums.com/topic/154#post-182 Wed, 10 Mar 2010 00:30:07 +0000 ziv.seemann 182@http://www.FEA-Forums.com/ <p>Hello I'm a new user with comsol but i know my way around,<br /> I need to solve a heating problem in a closed space.</p> <p>In order to do so I'm using comsol multiphysics - incompressible naviar stokes and convection and conduction.</p> <p>After defining the geometry, boundary and subdomains I solved the heat only and then the whole problem, I got an error something like sqrt(-1).<br /> see file at <a href="http://rapidshare.com/files/361389700/didnt_work.mph" rel="nofollow">http://rapidshare.com/files/361389700/didnt_work.mph</a></p> <p>Where did I go wrong?</p> <p>And another question:<br /> If I'm trying to use a fan and I want to set the boundary I have only velocity boundary that fits,<br /> But I need to enter a source (Q) to the equation so how do I do it?</p> <p>I'm attaching the file that i made</p> <p>Thanx!!!!!!! </p> http://www.FEA-Forums.com/topic/153#post-181 Wed, 03 Mar 2010 19:47:23 +0000 sribara 181@http://www.FEA-Forums.com/ <p>Hi all,<br /> I wonder how to perform Dynamic stress/shock wave analysis with ANSYS? It possible with ANSYS? I know, its possible with ALGOR. I want to perform a 2D and 3D stress wave simulation. Please help me on this regards... </p> http://www.FEA-Forums.com/topic/152#post-180 Tue, 02 Mar 2010 01:44:18 +0000 BrianBak 180@http://www.FEA-Forums.com/ <p>Hi </p> <p>I am trying to model the bridging effects of fibers crossing the crack opening in a interface crack problem. These crossing fibers put traction on the crack surface and the traction depends nonlinearly on the crack opening. In order to model this traction on the crack surface I would like to be able to make a nonlinear displacement/force law in the x,y and z direction, respectively, without any dependency between the three displacement/force laws. </p> <p>Does anyone know what can be done in Ansys to do this? </p> <p>Thanks in advance</p> <p>Regards Brian </p> http://www.FEA-Forums.com/topic/151#post-179 Tue, 23 Feb 2010 05:32:31 +0000 Silvia_Petkova 179@http://www.FEA-Forums.com/ <p>Hello,<br /> I have to "shake" my Model ( Soil - Steel pipe - Pressured Water) in WB, Flexible dynamic + CFX , MultiField Solver to solves FSI and I am at a loss: whether the using of Joint ("Soil "Body to Ground) and than applying Joint condition (acceleration time history along Z), in WB Simulation, is a good idea for transmission of “Seismic support excitation” or there is some better way? </p> http://www.FEA-Forums.com/topic/150#post-178 Mon, 22 Feb 2010 02:28:06 +0000 nashi_lg 178@http://www.FEA-Forums.com/ <p>HI ALL,<br /> i m doing a solid spherical multiple ball impact using LS DYNA keyword manual. could anyone tell me plz which card i should use for contact and control information so that ,the rebound effect of balls can be simulate. In my case balls are moving deeper inside the solid plate after losing kinetic energy. </p> <p>thanks<br /> naresh. </p> http://www.FEA-Forums.com/topic/149#post-177 Thu, 18 Feb 2010 05:22:08 +0000 Silvia_Petkova 177@http://www.FEA-Forums.com/ <p>Hello,<br /> I'd like to ask you for help, because I am trying desperately to solve my complicated model in Ansys Workbench. I am using Ansys MuliField external soler coupling, because the examined problem concerns Fluid - Pipe - Soil interaction.<br /> The model consists to submodel :<br /> • Structural , prepared in WB - soil block 20/6/11m , which enclouse steel pipe - D=1m, also the flexible analys steps are prepared in WB ( springs with stiffnes and damping connect the Soil Body to Ground along the four enclosure face; general joint has been put on the lower face and seismic support excitation - acceleration is applyed through it, than Ansys input file has been written)<br /> • the other model is the model of the fluid and it has been prepared and meshed with CFX Mesh, than the simulation type and the other steps are made and the coupled solver has been strarted, but the solution breaks off.................. :(<br /> Ansys Out File:<br /> *** WARNING *** CP = 1284.824 TIME= 16:42:47<br /> Pivoting option activated for Sparse Direct Solver. The memory<br /> required may greatly exceed predicted amount. In that event rerun<br /> with increased memory using -m option (refer to the Basic Analysis<br /> Procedures Guide, Ch. 19).<br /> Sparse solver maximum pivot= 6.872610448E+27 at node 48 UX.<br /> Sparse solver minimum pivot= -1.49352841E+30 at node 81283 ROTZ.<br /> Sparse solver minimum pivot in absolute value= 370396.354 at node 2074<br /> UZ. </p> <p> *** WARNING *** CP = 1549.449 TIME= 16:47:23<br /> There are 1987 small equation solver pivot terms.<br /> EQUIL ITER 1 COMPLETED. NEW TRIANG MATRIX. MAX DOF INC= -53.75 </p> <p> *** ERROR *** CP = 1554.378 TIME= 16:48:49<br /> One or more elements have become highly distorted. Excessive<br /> distortion of elements is usually a symptom indicating the need for<br /> corrective action elsewhere. Try ramping the load up instead of step<br /> applying the load (KBC,1). You may need to improve your mesh to<br /> obtain elements with better aspect ratios. Also consider the behavior<br /> of materials, contact pairs, and/or constraint equations. If this<br /> message appears in the first iteration of first substep, be sure to<br /> run shape checking of elements. </p> <p> *** WARNING *** CP = 1554.394 TIME= 16:48:49<br /> The unconverged solution (identified as time 0.5 substep 999999) is<br /> output for analysis debug purposes. Results should not be used for<br /> any other purpose. </p> <p>( CDF ) out file:</p> <p> +--------------------------------------------------------------------+<br /> | ERROR #001100279 has occurred in subroutine ErrAction. |<br /> | Message: |<br /> | cplg_SendCommand failed to send the command: NEXTSP </p> <p>I will be very grateful if you can Help me, thank you very much in advance! </p> <p>Silvia Petkova<br /> MSc CEng,<br /> Department of Hydraulic<br /> Engineering, UACEG<br /> 1, Hristo Smirnenski Blvd.,<br /> 1046 Sofia, BULGARIA </p> http://www.FEA-Forums.com/topic/148#post-176 Wed, 17 Feb 2010 12:06:18 +0000 CdriK 176@http://www.FEA-Forums.com/ <p>Hello,<br /> i do ten load step on Ansys, and when i change step, i must do a new nodal solu, for ploting the good scale of stress. If i don't do this, i always have the result for the first step.... It's normal, or i need to change something in my parameters?? </p> http://www.FEA-Forums.com/topic/147#post-175 Tue, 09 Feb 2010 11:54:50 +0000 maniferrari 175@http://www.FEA-Forums.com/ <p>I want to analyse a containment vessel having solid, beam and Shell elements. I know that beam and shell elements gets meshed. But how do i mesh the Solid to the beam element? Is there any way I could do that? </p> <p>Thanks </p> http://www.FEA-Forums.com/topic/144#post-174 Fri, 05 Feb 2010 05:14:44 +0000 pthieffr 174@http://www.FEA-Forums.com/ <p>Hi Jude,<br /> You can always use some APDL commands to do this. </p> <p>Pierre </p> http://www.FEA-Forums.com/topic/145#post-173 Fri, 05 Feb 2010 05:12:20 +0000 pthieffr 173@http://www.FEA-Forums.com/ <p>Sure. ANSYS has user defined element capability in form of so-called UPF (User Programmable Features). Check the doc and/or ask your locai support. </p> http://www.FEA-Forums.com/topic/146#post-172 Tue, 02 Feb 2010 04:09:36 +0000 Rudi 172@http://www.FEA-Forums.com/ <p>Hi,<br /> For several years now I've been doing simulations with plastic materials using the properties as if they were homogeneous. Recently I've discovered that it should be possible to include fiber orientation in the model. The results of a Moldflow analysis apparently can be used to achieve this. I'm using ANSYS for my structural simulations and wanted to inquire if they is anyone amonst the forum members that has experience with this topic.</p> <p>Any help, tip or information would be very welcome </p> http://www.FEA-Forums.com/topic/142#post-171 Mon, 01 Feb 2010 09:14:44 +0000 prakasbe 171@http://www.FEA-Forums.com/ <p>Hello sir,<br /> My Problem is finding out the vertical length of the ball when the pressure should be increased.</p> <p>I just create one rectangular (14*2) cm, below that the center of rectangular one half spherical ball at a radius=5cm is created. The half spherical ball and the rectangular is in point contact. . (It s 2D diagram)</p> <p>ELEMENT TYPE: solid- 4 node 182</p> <p>MATRL PROP: MTRL NO:1 (silicone Ball)- structural-nonlinear-elastic-hyperelastic-mooney rivilin-3 parameter c10=0.556,c01=0.038,c11=0,d=0.</p> <p>MTRL NO: 2 (rectangular)- linear- isotropic- E=2e5, prxy=0.3</p> <p>MESHING: Area - Mesh<br /> CONTACT MANAGER: I choose (surface-surface) target-ball face , contact- rectangular bottom face(flat line)</p> <p>SOLN: abridged menu-analysis option-NLGEOM-ON<br /> SOLN: define loads-structural-displacement-ALL DOF- on ball flat face.</p> <p>FORCE/MOMENT: pressure 15, flat face on the top of the ball<br /> After giving load i go for SOLN- solve current LS- (I got the answer is - The values of uy at node 1 is 3.387295E+11.It is greater than the current limit of 1000000.this generally indicates rigid body motion as result of an unconstrained model. If one or more parts of the model are held together only by contact verify that the CNCHECK commands to check the initial contact states in the solution module)<br /> I didn’t Know what mistakes i did..... </p> http://www.FEA-Forums.com/topic/145#post-170 Fri, 29 Jan 2010 11:58:29 +0000 msenousy 170@http://www.FEA-Forums.com/ <p>Hi there,<br /> I am wondering whether there is any capability in ANSYS so that I can add an element to its library, and call this element from within ANSYS.</p> <p>thx </p> http://www.FEA-Forums.com/topic/144#post-169 Mon, 25 Jan 2010 22:20:24 +0000 jude li 169@http://www.FEA-Forums.com/ <p>Hi,</p> <p>I am new to using Ansys Workbench 12.0 and need to measure the distance (straight line) between 2 points after a deformation. </p> <p>I have tried specifying the coordinates of my two points in a "Path", and apply a "Total Deformation" solution. However, the data is very inaccurate. </p> <p>Would there be another way of measuring the distance between 2 points on the model after deformation?</p> <p>I really appreciate your help. Thank you and God Bless.</p> <p>Jude </p> http://www.FEA-Forums.com/topic/142#post-168 Fri, 22 Jan 2010 09:54:18 +0000 sravan 168@http://www.FEA-Forums.com/ <p>that error usually comes when your problem is poorly constrained..... i'l try the problem and get back to you..... anyways check your constrains once more.... </p> http://www.FEA-Forums.com/topic/143#post-167 Fri, 22 Jan 2010 01:47:44 +0000 Sabaree 167@http://www.FEA-Forums.com/ <p>Greetings to all,</p> <p>I am trying to design a wheel hub. I made it as a 3D model and meshed using SOLID45 element. Now I want to apply the loads that are concentrated at the bottom and tapers towards the outer edge. If we are solving a problem with BEAM element, we can apply Varying Load by selecting "pressure on beam" and specifying 2 different values. How can we do the same thing, if modeled with SOLID element?<br /> Please help!!!!!</p> <p>Thanks in advance!!<br /> Regards </p> http://www.FEA-Forums.com/topic/142#post-166 Thu, 21 Jan 2010 23:00:44 +0000 prakasbe 166@http://www.FEA-Forums.com/ <p>Hi,<br /> My Problem is based on CONTACT ANALYSIS,I just create one half sperical ball at a radius=5cm,below that the centre of ball i create one rectangular(7*2)cm,the half ball is just touching that rectangular top face.</p> <p>ELEMENT TYPE: solid- 4 node 182</p> <p>MATRL PROP: MTRL NO:1 (Ball)- structural-nonlinear-elastic-hyperelastic-mooney rivilin-3 parameter c10=0.556,c01=0.038,c11=0,d=0.<br /> MTRL NO: 2 (rectangular)- linear- isotropic- E=2e5, prxy=0.3</p> <p>MESHING: Area - Mesh</p> <p>CONTACT MANAGER: I choose (surface-surface)target-rectangular top face(flat line), contact-ball face (curve line)</p> <p>SOLN: abriged menu-analysis option-NLGEOM-ON<br /> SOLN: define loads-structural-displacement-ALL DOF- on rectangular bottom Line.</p> <p>FORCE/MOMENT:50N Point load , flat face on the top of the ball</p> <p>After giving load i go for SOLN- solve current LS- (But the soln is not done,I got the answer is - The values of uy at node 1 is 3.387295E+11.It is greater than the current limit of 1000000.this generally indicates rigidbody motion as result of an unconstrained model. If one or more parts of the model are held together only by contact verify that the CNCHECK commands to check the initial contact states in the solution module)<br /> I didnt Know what mistakes i did..... </p> http://www.FEA-Forums.com/topic/141#post-165 Tue, 19 Jan 2010 06:00:55 +0000 AlexZinchenko 165@http://www.FEA-Forums.com/ <p>hi all!</p> <p>I have problems with .dxf import in COMSOL..</p> <p>even with the simplest 3d objects like sphere comsol import it as 2d image</p> <p>any suggestions?</p> <p>.dxf file I've created in Maple13<br /> does anybody know any other CAD program that can draw 3d surface by giving equation?</p> <p>please help,<br /> Alex </p> http://www.FEA-Forums.com/topic/140#post-164 Thu, 14 Jan 2010 14:45:52 +0000 ajdowdell 164@http://www.FEA-Forums.com/ <p>Wow... I've triple checked to make sure that is says axisymmetric, but I had to click it off, then return to axisymetric and i then corrected the thickenesses back to zero.. Frustrating.. </p> <p>Thanks! </p> http://www.FEA-Forums.com/topic/140#post-163 Thu, 14 Jan 2010 13:53:44 +0000 ajdowdell 163@http://www.FEA-Forums.com/ <p>I've got a sruface model, that has thickness = 0 in Design modeler. Then once I transfer it into simulation (in 2D mode accepting 0 thickness models only) some of the surface models gain a thickness specification that is assigned as 1. You cannot go in to the thickness field in the details box and set thickness to 0 because then it puts a ? infront of the object,and won't solve at all. Sometimes all objects are assign a thickness of 1, sometimes one object remains a true "thin" surface.</p> <p>In my little world since it's set on axisymetric, there should be NO option for a thickness. Assigning a thickness to an axisymetric thin model is not even really comprehensible... </p> <p>This if from the help menu:</p> <p>Importing Surface Body Thickness<br /> Surface body thickness will be imported from CAD (including DesignModeler) if, and only if, the existing surface body thickness value in Simulation is set to 0 (zero). This is true on initial attach and if you set the surface body thickness value to zero prior to an update. This allows you the flexibility of updating surface body thickness values from CAD or not.</p> <p>That to me means that the model must be correct coming out of DM into sim, and that the thickness has to be added in the simulation somewhere. </p> <p>Does any one know where the setting might be to change this or have any ideas? Thanks! </p> http://www.FEA-Forums.com/topic/139#post-162 Thu, 14 Jan 2010 10:21:16 +0000 abraham70 162@http://www.FEA-Forums.com/ <p>Finite Element Analysis of Vehicle and Tire has become a very important aspect of a tire design and failure analysis to most Tire companies. Tire modeling with ABAQUS is a very complicated process involving complex materials like hyperelastic rubber and textile reinforcements, large model size, prolonged simulation time and various convergence issues. This white paper intends to help in understanding the challenges in tire analysis and several tips and tricks that makes a difference in the quality of the results and processing time. AEG hopes that this article will be useful to ABAQUS users working in the field of tire design and analysis.</p> <p>Complete Article:<br /> <a href="http://www.engineering-group.com/technical_briefs.php" rel="nofollow">http://www.engineering-group.com/technical_briefs.php</a> </p> http://www.FEA-Forums.com/topic/138#post-161 Wed, 13 Jan 2010 22:36:02 +0000 cruss 161@http://www.FEA-Forums.com/ <p>Gents,</p> <p>I have a 3d part model that is described by a surface mesh. Can WorkBench convert this into a volume mesh? </p> http://www.FEA-Forums.com/topic/137#post-160 Wed, 13 Jan 2010 08:30:43 +0000 beyouna 160@http://www.FEA-Forums.com/ <p>i want to mesh my symmetric solid model which i had modeled with solidworks on ansys but i can't have a symmetric meshing.<br /> Please help me?<br /> Thanks </p> http://www.FEA-Forums.com/topic/136#post-159 Fri, 08 Jan 2010 02:11:04 +0000 nanandavalli 159@http://www.FEA-Forums.com/ <p>i want to obtain bending strains in beam element. how to extract from the results </p> http://www.FEA-Forums.com/topic/135#post-158 Tue, 05 Jan 2010 11:08:38 +0000 hellofea 158@http://www.FEA-Forums.com/ <p>Hi,<br /> there are so many FEA software. I am not sure where the position of Cosmos. Could we rely on Cosmos simulation result? What is the limitation of Cosmos?<br /> Thanks,<br /> Johnson </p> http://www.FEA-Forums.com/topic/134#post-157 Wed, 30 Dec 2009 21:18:39 +0000 wizardz 157@http://www.FEA-Forums.com/ <p>I have some problem in electrostatic coupled-field analsys.</p> <p>I have a MEMS capacitive actuator which incorporates irregulator shapes of air. I use 2D simulation now. </p> <p>Is it always necessary to set the edge to air to UX,UY to zero?</p> <p>I sometimes observed very weird large deformation of air. If I do not define the edge of air to UX,UX zero, the deformed shape sometimes show that the inside node will leave away from the air material.</p> <p>Thanks! </p> http://www.FEA-Forums.com/topic/130#post-156 Mon, 28 Dec 2009 21:06:20 +0000 dharanendrad 156@http://www.FEA-Forums.com/ <p>Hi, You have to use connection feature. In that, there are method to establish contact between surfaces. </p> http://www.FEA-Forums.com/topic/133#post-155 Sat, 19 Dec 2009 07:26:38 +0000 AcoidanBM 155@http://www.FEA-Forums.com/ <p>Hi there<br /> I have one problem trying to run an analysis on Ansys v12. I have imported and meshed a geometry from catia in IGS format. But, when I try to solve the problem, this warning message appears:<br /> A load transfer error was occurred. A load could not be applied to small or defeatured entity. ...</p> <p>I have tried to do what is writen in the troubleshooting, (changing to other entity or with a finest mesh), but I can't success.</p> <p>Do you know if there is a solution to this problem?</p> <p>Thank you very much </p> http://www.FEA-Forums.com/topic/132#post-154 Sat, 19 Dec 2009 07:14:09 +0000 AcoidanBM 154@http://www.FEA-Forums.com/ <p>Hi there<br /> I have one problem trying to run an analysis on Ansys v12. I have imported and meshed a geometry from catia in IGS format. But, when I try to solve the problem, this warning message appears:<br /> A load transfer error was occurred. A load could not be applied to small or defeatured entity. ...</p> <p>I have tried to do what is writen in the troubleshooting, (changing to other entity or with a finest mesh), but I can't success.</p> <p>Do you know if there is a solution to this problem?</p> <p>Thank you very much </p> http://www.FEA-Forums.com/topic/131#post-153 Fri, 11 Dec 2009 12:25:39 +0000 s_ali_ef 153@http://www.FEA-Forums.com/ <p>Hi all<br /> I have a question.<br /> If it is possible to save damping matrix for model as an output file?<br /> I want to save damping model then open that by Matlab.<br /> Please email me if possible by :<br /> <a href="mailto:s_ali_ef@yahoo.com">s_ali_ef@yahoo.com</a><br /> Best wishes </p> http://www.FEA-Forums.com/topic/130#post-152 Mon, 07 Dec 2009 20:44:52 +0000 dhill 152@http://www.FEA-Forums.com/ <p>Using Ansys workbench, i have two parts in a simulation where one part deflects through the other part. How do i keep them from passing through each other? </p> http://www.FEA-Forums.com/topic/129#post-151 Thu, 03 Dec 2009 13:06:37 +0000 pday 151@http://www.FEA-Forums.com/ <p>I am fairly new to ANSYS and have been trying to model the interaction between glass micro-spheres and silicone polymer micro-structures for my dissertation research. I've been working through the online manual, but have been getting very odd results when running the simulation. Any help at all would be appreciated. The summary of my problem is as follows:</p> <p> Modelling:</p> <p>It may help to first refernce the first two images at : <a href="http://bdml.stanford.edu/twiki/bin/view/Main/AnsysModelling" rel="nofollow">http://bdml.stanford.edu/twiki/bin/view/Main/AnsysModelling</a></p> <p>I have a single, thin wedge shape modelled with SOLID95 elements. The body of the wedge (everything but the round tip) is comprised of 20-node bricks. The rounded top of the wedge is modelled with 10-node tetrahedron, with pyramidal interface eelements between the tets and the bricks. The material model for the wedge is a linear isotropic one with ballpark values of: E=1e6 and PR=0.49. I also gave it a friction coefficient of 1.</p> <p> Contact Elements: </p> <p>The contact surface is showin the third picture in the above link. </p> <p>I set the type to CONTA174 and, using the meshing tool, meshed the shown areas with triangular elements on the round top of the wedge, and quad elements on the front face. I then set the R1 value in the real constant set to the desired radius of my sphere, which is the rigid target. Using the same real constant set, I set the type to TARGE170 and created a pilot node element where I wanted the center of the sphere and then created a sphere element on top of the pilot node. The sphere was the appropriate size, so I believe the shared real constant set is correctly set up. </p> <p> Simulation:</p> <p>I constrained the bottom of the wedge in all DOF, and put a simple displacement load on to the pilot node of the sphere. I want the sphere to move straight down a certain distance, and observe how the wedge deforms. I didn't change much in the way of thesolution controls. I set it up as a large displacement static problem with a 250 set as the number of substeps and 150 as the minimum number of substeps. The simulation fails each time, however, due to an error in element formulation. It's easy to see why there is an error when I plot the deformed shape of the last solution set. The elements become highly distorted almost as soon as the target comes in to contact with the contact surface. This can be seen in the last image in the link above. </p> <p>As I said before, I'm a bit new to contact simulation in ANSYS. Maybe I've made a silly, rookie error. Any guidance at all would be greatly appreciated. </p> <p>Paul </p> http://www.FEA-Forums.com/topic/128#post-150 Mon, 23 Nov 2009 04:59:55 +0000 cubancigar11 150@http://www.FEA-Forums.com/ <p>Hi!</p> <p>Is there any way to use Fortran 90 for usermat files, instead of Fortran 77?</p> <p>Regards, </p> http://www.FEA-Forums.com/topic/127#post-149 Sat, 21 Nov 2009 15:48:27 +0000 ivan1 149@http://www.FEA-Forums.com/ <p>Hi:<br /> I´m spanish, so my english is bad, excuse me.<br /> I have a problem when I like input a alternate load.<br /> I would like make a fatigue simulation on a component. Load is 1200N to left, and after 600N to right, along 50000 cycles.<br /> Please, How I make it!<br /> Thanks! </p> http://www.FEA-Forums.com/topic/126#post-148 Sun, 15 Nov 2009 23:08:07 +0000 scvan 148@http://www.FEA-Forums.com/ <p>Im a 4th year Engineering student and I've had some introdution to hull girder analysis at Uni using Ansys. I was wondering if anyone could tell me what would be the recommended FE software apckage for doing a global analysis of ship Hull. </p>