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<p>I am trying to make a simulation where I only need a fine region near the center, and no fine region anywhere else. But the workbench LS DYNA just divides it into equal cubes. Is there a way to tweak that or will i have to use LS prepost? </p>
<p>I have been running some asysimmetric and 3D simulations of detonations in cyllinders and ran into the problem that the detonation shockwave travels radially, not stopping at any barriers. This is unphysical. I am using all Euler mesh, Explicit Dynamics solver. Default C4 material in the Explicit Materials tab, and steel 4340 as the wave shaper (the lead barrier). The following are diagrams of what I have been observing. Does anyone know why is this happening and how to prevent them from happening? Following are plots of pressure, where detonation happens in the lower corner, next to axis of symmetry, but the detonation wave just travels radially outwards, neglecting the barrier and the void. </p><p> </p><p> </p><p></p>
<p>I used the S-ALE algorithm to complete the solution, and when I used LS PrePost to view the d3plot file, I found that the fluid profile is hollow. How should I set it up to see the solid profile?</p>
<p><p>Hello, I am trying to create an example model to represent the workflow for a one-way thermal mechanical model where I run the thermal part first to basically map a temperature field to a body. secondly, I want to transfer this temperature field to the structural step so the stiffness of the structure is altered by this temperature field. I want to ask about the load_thermal_binout file.</p><p>1) if I run in SMP, can I not use load_thermal_binout?</p><p>2) if I run in MPP, I have a binout file by default. However, when I load the data, the solver just crashes with no messages</p><p>3) below is the exact keyword I used but maybe I have an issue with the alignment of time steps. ...</p><p class="MsoNormal">*LOAD_THERMAL_BINOUT</p><p class="MsoNormal">$# deftemp</p><p class="MsoNormal"> 273.15</p><p class="MsoNormal">$# filename</p><p class="MsoNormal">thermalstep.binout0000</p><p class="MsoNormal">$ $ startt tsf tmpoff nidoff</p><p class="MsoNormal">$ 0 1.0 0.0 0</p><p> </p></p>
<p><p><p>Hi, I was doing an impact analysis in LS-DYNA Workbench. I am giving pressure value to a rod to impact outer body. However, when I add velocity the model works truly. When I add pressure bodies penetrate. I checked the contacts. I am using keywords and I am sure that they are correct. What can be the problem?</p></p></p>
<p>Hello everyone, I'm very glad to ask questions here.</p><p>I would like to ask, when using LS-DYNA software to simulate the pulsation of underwater bubbles in 2D plane, can only the ALE element type with Y-axis symmetry be used for the fluid model? I want to study the impact of bubble pulsation on a steel plate. I want to place the steel plate in front of the explosive (as shown in the figure). In this case, can only the SOLID element type with Y-axis symmetry be selected for the steel plate? If so, won't the left and right sides be affected by the reflection of the shock wave when symmetrical? Can a full-size model without symmetry be made as a large plane? If so, how should the element type be selected?</p><p>Thank you all.</p><p></p>
<p>Hi Forum,</p><p>I can't seem to find a lot of information about the multi-material ALE interface reconstruction process in the manual and want to understand how my simulations are handling the interfaces between 2-3 materials. I found some materials online from Dr. Hao Chen, but I'm not if it is just generating a new cut plane at each time step given updated volume fractions within a given cell or is it actually tracking the surface akin to a level-set method? </p><p>Peter</p>
<p>Hi. I am trying to run a simulation of low velocity impact on composite in LSDYNA, ANSYS Workbench. A composite body (flexible) modeled in ACP and a impactor body (rigid) modeled in mechanical model in present here. I am getting SPH errors.<br><br>If I convert the impactor to a flexible body with high stiffness the simulation runs well though I will have to validate the results. But changing to rigid body is causing this SPH errors. I am not familiar with this error and cant figure out what's causing them.<br><br>I can consider SPH but even then there is a negative mass error. All the pictures are attached here.<br>Any help will be much appreciated. Thanks.</p><p></p><p></p><p></p>
<p>Hello!</p><p>I am trying to simulate a seatbelt tightening process around a seat that is modeled as a rigid body using solid tetrahedral elements and MAT_20 material. Since I do not want the rigid body to be displaced, I applied constraints in all directions to this material. I've applied a boundary-prescribed motion to a piece of seatbelt (modeled using shell elements as MAT_FABRIC) that tries to tighten the seatbelt around this rigid body. I've defined different types of contacts between these bodies, but the contact keeps breaking, and the seatbelt goes right through the rigid body. If I use a deformable material to define my seat, the contacts work appropriately. Any help on trying to resolve this issue would be great!</p><p>Thanks!</p>
<p>I am trying to make a simulation where I only need a fine region near the center, and no fine region anywhere else. But the workbench LS DYNA just divides it into equal cubes. Is there a way to tweak that or will i have to use LS prepost? </p>
<p>I have been running some asysimmetric and 3D simulations of detonations in cyllinders and ran into the problem that the detonation shockwave travels radially, not stopping at any barriers. This is unphysical. I am using all Euler mesh, Explicit Dynamics solver. Default C4 material in the Explicit Materials tab, and steel 4340 as the wave shaper (the lead barrier). The following are diagrams of what I have been observing. Does anyone know why is this happening and how to prevent them from happening? Following are plots of pressure, where detonation happens in the lower corner, next to axis of symmetry, but the detonation wave just travels radially outwards, neglecting the barrier and the void. </p><p> </p><p> </p><p></p>
<p>I used the S-ALE algorithm to complete the solution, and when I used LS PrePost to view the d3plot file, I found that the fluid profile is hollow. How should I set it up to see the solid profile?</p>
<p><p>Hello, I am trying to create an example model to represent the workflow for a one-way thermal mechanical model where I run the thermal part first to basically map a temperature field to a body. secondly, I want to transfer this temperature field to the structural step so the stiffness of the structure is altered by this temperature field. I want to ask about the load_thermal_binout file.</p><p>1) if I run in SMP, can I not use load_thermal_binout?</p><p>2) if I run in MPP, I have a binout file by default. However, when I load the data, the solver just crashes with no messages</p><p>3) below is the exact keyword I used but maybe I have an issue with the alignment of time steps. ...</p><p class="MsoNormal">*LOAD_THERMAL_BINOUT</p><p class="MsoNormal">$# deftemp</p><p class="MsoNormal"> 273.15</p><p class="MsoNormal">$# filename</p><p class="MsoNormal">thermalstep.binout0000</p><p class="MsoNormal">$ $ startt tsf tmpoff nidoff</p><p class="MsoNormal">$ 0 1.0 0.0 0</p><p> </p></p>
<p><p><p>Hi, I was doing an impact analysis in LS-DYNA Workbench. I am giving pressure value to a rod to impact outer body. However, when I add velocity the model works truly. When I add pressure bodies penetrate. I checked the contacts. I am using keywords and I am sure that they are correct. What can be the problem?</p></p></p>
<p>Hello everyone, I'm very glad to ask questions here.</p><p>I would like to ask, when using LS-DYNA software to simulate the pulsation of underwater bubbles in 2D plane, can only the ALE element type with Y-axis symmetry be used for the fluid model? I want to study the impact of bubble pulsation on a steel plate. I want to place the steel plate in front of the explosive (as shown in the figure). In this case, can only the SOLID element type with Y-axis symmetry be selected for the steel plate? If so, won't the left and right sides be affected by the reflection of the shock wave when symmetrical? Can a full-size model without symmetry be made as a large plane? If so, how should the element type be selected?</p><p>Thank you all.</p><p></p>
<p>Hi Forum,</p><p>I can't seem to find a lot of information about the multi-material ALE interface reconstruction process in the manual and want to understand how my simulations are handling the interfaces between 2-3 materials. I found some materials online from Dr. Hao Chen, but I'm not if it is just generating a new cut plane at each time step given updated volume fractions within a given cell or is it actually tracking the surface akin to a level-set method? </p><p>Peter</p>
<p>Hi. I am trying to run a simulation of low velocity impact on composite in LSDYNA, ANSYS Workbench. A composite body (flexible) modeled in ACP and a impactor body (rigid) modeled in mechanical model in present here. I am getting SPH errors.<br><br>If I convert the impactor to a flexible body with high stiffness the simulation runs well though I will have to validate the results. But changing to rigid body is causing this SPH errors. I am not familiar with this error and cant figure out what's causing them.<br><br>I can consider SPH but even then there is a negative mass error. All the pictures are attached here.<br>Any help will be much appreciated. Thanks.</p><p></p><p></p><p></p>
<p>Hello!</p><p>I am trying to simulate a seatbelt tightening process around a seat that is modeled as a rigid body using solid tetrahedral elements and MAT_20 material. Since I do not want the rigid body to be displaced, I applied constraints in all directions to this material. I've applied a boundary-prescribed motion to a piece of seatbelt (modeled using shell elements as MAT_FABRIC) that tries to tighten the seatbelt around this rigid body. I've defined different types of contacts between these bodies, but the contact keeps breaking, and the seatbelt goes right through the rigid body. If I use a deformable material to define my seat, the contacts work appropriately. Any help on trying to resolve this issue would be great!</p><p>Thanks!</p>
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