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<p>Hello, everyone</p><p>I ran a job in ls-run. The status displayed terminated first and then finished. And it displays normal termination. I didn't find any error message in the messag file and .out file. Is that normal? Or it indicates that there are some errors?</p><p></p><p> </p>

<p>I have created fluid meshes to run FSI many times before but suddenly the mesh to MS mesh is not working anymore.  It causes an element or two to either extend very long or dissapear. Any advice or anyone else dealing with this? </p><p> </p><p>It may be irrelavent but I also recently started having visual plotting issues when viewing the result files. Thanks</p>

<p><p>I'm simulating the axial crushing of a tube in ANSYS LS-DYNA Mechanical (2025 R2 Teaching license). While the analysis is working very well, I can't get reaction forces on either side of the tube.</p><p>The setup I'm using consists of a plate as an "anvil", the axial tube, and a block as a "hammer", which has velocity and gravitational conditions applied. To calculate the energy absorbed by the deformation, I need to integrate the force over the deformation of the tube. I can easily get data for how much the tube has deformed from the displacement of the 'hammer', but I'm having difficulty getting the force of the hammer on the tube. I would usually measure this between the tube and 'anvil' plate. If I explore Results →Worksheet, it appears that forces are not a user-defined result that I can directly get.</p><p>Is there a way of getting reaction forces on the supports on the plate, or of getting the contact force between the tube and plate directly? At the moment I'm getting the average pressure across the surface to calculate the force, but this is not seeming quite accurate - or should it be?</p></p>

<p>I'm having some difficulty in controlling the time step for results in a simulation I'm doing.</p><p>I'm trying to model a square tube being axially crushed by an impact load, and while the results I have match experimental results fairly well, I need finer time steps between results. I'm getting these results from "Tabular Data" under each solution. The end time for the analysis is 40ms, and the tabular data only shows data for every 2ms, despite my best efforts to change this. I've tried changing time history output controls and mesh size (global and specific body sizing) but these only change the time steps in the "Solver Output", and don't actually show me more detail in the individual results' tables.</p><p>Am I missing a better way of exporting this that might show smaller jumps between each data point, or will Tabular Data show me all the detail (if I configure things correctly)?</p><p>I'm on Ansys 2025 R2, on the Teaching license.</p>

<p>Hi everyone,</p><p>I’m modeling a transient impulse load on a cantilever beam in ANSYS Mechanical (LS-DYNA). The goal is to apply a 20,000 N load on the free end of the beam for 0.005 seconds, and then release it so that the beam vibrates freely.</p><p>When I perform the same simulation in Explicit Dynamics, the motion looks physically correct, the beam deflects under the short pulse and then oscillates freely around zero displacement.</p><p>However, in LS-DYNA, the deformation and stress results differ.<br>The amplitude of the oscillation is not consistent with the expected physical response,<br>and the displacement does not start at zero even though the loading is transient and begins at time = 0.</p><p>Current LS-DYNA Keyword setup:</p><div style="padding-left: 40px;"><span style="font-size: 12pt;">*DEFINE_CURVE_TITLE</span></div><div style="padding-left: 40px;"><span style="font-size: 12pt;">LoadPulse</span></div><div style="padding-left: 40px;"><span style="font-size: 12pt;">1001,1,1.0,1.0</span></div><div style="padding-left: 40px;"><span style="font-size: 12pt;">$ time(s), pressure(N/mm^2)</span></div><div style="padding-left: 40px;"><span style="font-size: 12pt;">0.000, 2.0</span></div><div style="padding-left: 40px;"><span style="font-size: 12pt;">0.001, 2.0</span></div><div style="padding-left: 40px;"><span style="font-size: 12pt;">0.002, 2.0</span></div><div style="padding-left: 40px;"><span style="font-size: 12pt;">0.003, 2.0</span></div><div style="padding-left: 40px;"><span style="font-size: 12pt;">0.004, 2.0</span></div><div style="padding-left: 40px;"><span style="font-size: 12pt;">0.005, 2.0</span></div><div style="padding-left: 40px;"><span style="font-size: 12pt;">0.006, 0.0</span></div><div style="padding-left: 40px;"><span style="font-size: 12pt;">0.050, 0.0</span></div><div style="padding-left: 40px;"> </div><div style="padding-left: 40px;"><span style="font-size: 12pt;">*SET_SEGMENT_TITLE</span></div><div style="padding-left: 40px;"><span style="font-size: 12pt;">hej</span></div><div style="padding-left: 40px;"><span style="font-size: 12pt;">*LOAD_SEGMENT_SET</span></div><div style="padding-left: 40px;"><span style="font-size: 12pt;">1,1001,1.0</span></div><div> </div><div>Notes to understand code:</div><div style="padding-left: 40px;"><span style="font-size: 12pt;">The loaded surface area is 10,000 mm², </span><span style="font-size: 12pt;">so 2.0 N/mm² corresponds to a total load of 20,000 N.</span><br><span style="font-size: 12pt;">Named Selection = hej.</span></div><div><p>What is going wrong , is my keyword setup incorrect, or am I using *LOAD_SEGMENT_SET in the wrong way? </p><p>Specifically:</p>Is this the correct approach to apply a transient surface pressure in LS-DYNA Mechanical?Do I need to include any additional control cards or database options to get a proper transient response?Is there a better way to define a force (N) rather than pressure (N/mm²) on a surface?<p>I will attach:</p>Plots of the expected response (from Explicit Dynamics)Plots of the current LS-DYNA resultsPictures of named selection and fixed support<p>Any advice on what might be missing or incorrect in this keyword definition would be greatly appreciated.</p><p>// Ahmad Jaber, Industrial Engineering, Student Research Assistant, Örebro University</p><p></p><p></p><p></p><p></p><p></p><p> </p></div>

<p>Hello, is there any way in LS_Dyna to define a viscoelastic material which has constant storage and loss modulus? E*=E0(1+n i)</p>

<p data-start="100" data-end="351">Hi,<br data-start="103" data-end="106">I’m simulating a blast and its propagation through soil. I want to apply <em data-start="181" data-end="211">transmit boundary conditions to the sides and bottom of the model. However, when the calculation starts in <strong data-start="290" data-end="301">AUTODYN, I get a <strong data-start="311" data-end="342">“Negative density in state” error.</p><p data-start="358" data-end="395">Do you know how I can fix this issue?</p><p></p>

<p>Hello, I am simulating the glass penetration by bullet where I am interested in having the output data of the residual velocity of the bullet. The bullet is taken as the rigid body as at first when I tried outputing the surface velocity, it behaved anomaliously due to deformations. I am actually specifically interested in the normal velocity of the bullet that would be coupled with the center of the mass and not the surface. This is important as the bullet starts spinning after it exists the target, thus giving me the wrong values. Is it possible to achieve this without adding the script inside the explicit dynamic tool? </p>

<p>Hello, </p><p>I have a drop-impact simulation of a Glass+Plastic (polycarbonate) assembly. I'm get results that look like the Polycarbonate is undergoing plastic deformation.</p><p>However, I have limited experience validating plastic deformation in LS-DYNA and would like some help on this. I'm especially worried if i've artificially introduced some non-physical plastic deformation in my attempts to eliminate Hourglass energy. </p><p><span style="text-decoration: underline;">Setup:</span></p>Materials: Glass - Proprietary (substrate) , Plastic, PC High viscosity - Ansys default library (around the glass perimeter) , Steel - Default library(rigid body- shell) Contacts:Glass <-> PC : Shared topologyPC <-> Plate : FrictionalBehavior: AsymmetricFormulation: Pure Penalty (Automatic_nodes_to_surface)Viscous damping coefficient: 0.1Contact / Target Penalty Scale Factors: 10 Soft Constraint Formulations: Segment BasedSoft constraint Scale Factor: 1Depth: 2Mesh: Hex8 (for glass, PC), and Quad4 (plate)Hourglass controls: PC: ID 7 (Belytschko-Bindeman Linear Total Strain), coefficient = 1Element Controls:PC: Fully Integrated S/R SolidAnalysis setting:Global Hourglass control: ID 5 (Exact Volume Flanagam-Belytschko Stiffness Form), coefficient = 0.1<p>Points to note / Concerns: </p>High distortion of the PC (not sure how I can check this is actually physical/ potential mesh issue)The contact energy increases and stays high (I think this is ok since there's sliding at the frictional interface)Internal energy stays high after impact (again, I think this is physical since there's work done on the PC layer)<p><br></p><p></p><p></p>

<p>I am in the process of building a strongly coupled implicit FSI (with ICFD) model of an aortic valve, studying the effect of fibre orientation using the MAT_295 HGO model. I believe this material model requires me to use solid leaflets, as shells are not supported (yet). This makes it more difficult, though. When the solid leaflets touch, the fluid surface mesh follows and touches as well, which leads to penetration of the fluid mesh. With shells, this is not an issue, since the shell thickness ensures that there is an offset, ensuring that the fluid surface meshes do not touch. I tried many things, like SLDTHK of 0.1/0.25 mm (solid leaflets thickness being 0.25 mm), but this would easily lead to a blow-up due to the contact. This is the current contact keyword card:<br><br></p><p></p><p> </p><p>Does anyone have an idea I could try? Thanks a lot in advance!!</p>