https://community.cadence.com/cadence_technology_forums/physical-system-simulation/marc/en-USTelligent Community 13https://community.cadence.com/cadence_technology_forums/physical-system-simulation/marc/f/marc/74181/switching-the-thermal-properties-in-lpbf-simulation/1434943Wed, 07 Oct 2026 09:59:00 GMT75bcbcf9-38a3-4e2e-b84b-26c8c46a9500:d73cece5-3dde-41a9-9e46-b733a5dd2deePrintPilot PathfinderAyush / Shank, jumping in late on this. The open gap still looks like the irreversible consolidation-flag problem continuum LPBF thermal models hit when properties are temperature-only. Shank is right: you need a history/state variable that records that this integration point has melted at least once. Thermal conductivity, specific heat, density, whatever you are switching, has to depend on temperature plus that flag, not temperature alone. Pure T-tables always walk back into the powder branch on cool-down, which is exactly what you are seeing on later layers too. A pattern that usually works: 1. Add one state variable, say melted, initialized to 0 (powder) with INITSV or whatever initial-state path you use. 2. Each increment, if T is at or above your melt criterion (often liquidus, or solidus / liquid fraction for alloys with a mushy zone), set melted = 1 and never clear it (NEWSV / CHANGE STATE style, or whatever Marc thermal path lets you write state from a user routine). 3. Property selection: if melted is 0, use the powder/liquid tables vs T. If melted is 1, use the solid/liquid tables vs T only, and never go back to powder even when cold. That gives powder to liquid to solid as a one-way consolidation. Later reheat only moves between solid and liquid. Some papers track a continuous consolidated fraction equal to the historical max liquid fraction between solidus and liquidus, instead of a binary flag. Same idea: once consolidated, never return to powder. On HYPELA2: your read matches what I would expect. It is for mechanical constitutive behavior, so it is a poor fit for a pure thermal run. I would stay in the thermal/state-variable path (INITSV / NEWSV and related state options in Volume D) rather than forcing a mechanical hyperelastic routine into heat transfer. I do not have a ready-made Marc sample deck for this specific LPBF flag, so take the above as modeling logic rather than a drop-in subroutine name. If anyone on the board has a thermal-only state update example for property switching, that is the missing piece Ayush asked for after Shank's reply. Curious whether you already tried a two-table setup gated by a state variable, or whether the blocker has been finding which thermal user entry point is allowed to write that state each increment.https://community.cadence.com/cadence_technology_forums/physical-system-simulation/marc/f/marcTue, 29 Sep 2026 14:43:00 GMT75bcbcf9-38a3-4e2e-b84b-26c8c46a9500:40c44a4b-7119-4a67-9f3e-89735fbc8b56https://community.cadence.com/cadence_technology_forums/physical-system-simulation/marc/Tue, 29 Sep 2026 14:43:00 GMT75bcbcf9-38a3-4e2e-b84b-26c8c46a9500:12f7f7dc-c17e-4bda-b3ad-abd1c6461b15https://community.cadence.com/cadence_technology_forums/physical-system-simulation/marc/f/marc/74289/dynamic-transient-analysis-sudden-drop-in-initial-angular-velocity-using-rbe2-disc-brake/1432728Tue, 16 Jun 2026 08:45:00 GMT75bcbcf9-38a3-4e2e-b84b-26c8c46a9500:03641443-c5a5-4959-b632-8fa56fac5f80Shank KulkarniHi Sushant, its probably because of adaptive time stepping. Can you give it a try with fixed time stepping? Also, would be best to use table for initial velocity where velocity linearly increases from zero and then holds constant to the desired value.https://community.cadence.com/cadence_technology_forums/physical-system-simulation/marc/f/marc/74289/dynamic-transient-analysis-sudden-drop-in-initial-angular-velocity-using-rbe2-disc-brakeFri, 12 Jun 2026 02:06:00 GMT75bcbcf9-38a3-4e2e-b84b-26c8c46a9500:704abb7c-db38-4333-b7da-ccf8ac3512eeSushant GaikwadHi everyone, I am working on a transient dynamic disc brake simulation in Marc, and I’m running into an issue with the initial free rotation of the disc prior to brake contact. My goal is to have the disc spin freely at a constant initial angular velocity of 104.72 rad/s (1000 RPM) before the brake pads engage to stop it. However, the disc is not maintaining this constant speed. The angular velocity suddenly drops from 104.72 rad/s to a negative value, and then ramps back up to stabilize around 32–34 rad/s. Here is the breakdown of my model setup: Geometry & Material: Dimensions: Hollow disc with OD 100 mm, ID 50 mm, Thickness 10 mm. Material: Steel (Linear Elastic) — E = 210 GPa, Poisson’s ratio = 0.3, Density = 7850 kg/m³. Kinematics & Boundary Conditions: Connections: Using RBE2 elements tied to the inner bore of the disc. All DOF (X, Y, Z, Rx, Ry, Rz) at the inner bore are tied to a single central Master Node. Boundary Conditions: Fixed displacement applied to the Master Node in space. X, Y, Z, Rx, and Rz are fixed (0). Only the axis of rotation (Ry) is left free. Initial Conditions: An initial angular velocity of 104.72 rad/s is applied to the Master Node about the Y-axis. Loadcase Setup: Type: Structural Dynamic Transient. Time Stepping: Adaptive time control. My primary concern: I need the disc to hold its constant 104.72 rad/s rotation without dropping until the contact friction from the brake is introduced. Has anyone experienced this sudden velocity drop with rotating RBE2 setups in dynamic transient runs? Could this be an artifact of my adaptive time stepping, numerical damping, or how the initial velocity is being transferred from the master node to the RBE2 tied nodes? Any insights or suggestions would be greatly appreciated! Thanks in advance.Nonlinearthermal simulationMarcwearhttps://community.cadence.com/cadence_technology_forums/physical-system-simulation/marc/f/marc/74284/python-scripting-menu-system-lookup-function/1432720Tue, 02 Jun 2026 07:04:00 GMT75bcbcf9-38a3-4e2e-b84b-26c8c46a9500:ab9ccd69-cce3-478c-bef4-20fd42ec46adNils LangeI found some solution by myself. In "C:\Program Files\MSC.Software\Marc\XXXX.X\mentatXXXX.X\menus" you can find the entries manually. However whats that with the "F2 trick". How is that working?https://community.cadence.com/cadence_technology_forums/physical-system-simulation/marc/f/marc/74284/python-scripting-menu-system-lookup-functionTue, 02 Jun 2026 05:10:00 GMT75bcbcf9-38a3-4e2e-b84b-26c8c46a9500:ea392d14-6ace-4638-bd9c-1f10240876c3Nils LangeHello all, I have a question. I want to write a Python Script for a certain Automatization in Mentat Preprocessing. I'm quite familiar with Python + Mentat and wrote some scripts which work well. Now I want to get some information, in this case the node IDs and their coordinates inside Servo Link Ties. The documentation states in (Marc 2025.2 > Python: Tutorial and Reference Manual > PyMentat > Menu System Lookup Functions > Menu System Lookup Functions) that I have access to the database behind Mentat (Thats how I understand it), but somehow its not working for me. I'm using Windows. It says if my cursor is on the specific menu item (lets say the node ID which I want to get) then to press "F2". Then nothing happens for me when supposedly it should give me the key. For Windows it tells to go to the " UTILS->SIZES menu", however I dont even know where that is... Thanks for helping me, kind regards Nils Langehttps://community.cadence.com/cadence_technology_forums/physical-system-simulation/marc/f/marc/74252/stress-versus-strain-data-in-mat-file/1432641Fri, 10 Apr 2026 02:06:00 GMT75bcbcf9-38a3-4e2e-b84b-26c8c46a9500:c12d9c14-d102-41c1-bd0b-4b758a21f86bKiranraj ShettyDear Michal Lukac , Marc expects the plasticity table data in equivalent plastic strain vs true stress form. True stress = eng stress * (1+ engg strain) 'Total true strain = ln(1+engg strain) Plastic strain = total true strain - (E/True stress) Hence the first point in this table will always be (0, yield stress) Use below format to convert the engg stress strain data to Marc data, Make sure in the material properties menu, you use yield stress 1 while using actual plasticity data in the table. Regards, Kiranhttps://community.cadence.com/cadence_technology_forums/physical-system-simulation/marc/f/marc/74252/stress-versus-strain-data-in-mat-fileThu, 09 Apr 2026 14:29:00 GMT75bcbcf9-38a3-4e2e-b84b-26c8c46a9500:7cf29e4e-4883-470e-8b33-3dfce1f78947Michal LukacHi, I need to use my own matarial data for elastic-plastic analysis. I have Stress - strain curve from test data, So I calculateed True strain and true stress according to equations: σ_true = σ_test*(1+ε_test) and ε_true = ln(1+ε_test) from the ε_true values is then subtracted ε_true at σ_yield. So I have ε_true from 0 to e.g. 0.105 and σ_true from σ_yield to e.g. 1400. But in the original marc mat files the ε_true is from 0 to 1.0 So do I do something wrong or can I use the calculated data? Thanks for help m.plasticity datahttps://community.cadence.com/cadence_technology_forums/physical-system-simulation/marc/f/marc/74238/elevar-subroutine/1432609Tue, 24 Mar 2026 08:47:00 GMT75bcbcf9-38a3-4e2e-b84b-26c8c46a9500:26744e62-ee14-4459-9ab7-fb36da449187Shank KulkarniHi Ayush, I have written small article about how to use NODVAR subroutine in Marc. So not exactly same but NODVAR works in similar fashion. Gave example as well there. Please take a look and see if that helps. Link: https://simcompanion.hexagon.com/customers/s/article/How-to-use-NODVAR-subroutine-in-Marc-Mentat Regards, Shankhttps://community.cadence.com/cadence_technology_forums/physical-system-simulation/marc/f/marc/74238/elevar-subroutineTue, 24 Mar 2026 05:16:00 GMT75bcbcf9-38a3-4e2e-b84b-26c8c46a9500:e4531f13-cf9d-4fe1-8a94-fb9758276aaeAyush SrivastavaHi, I am trying to run ELEVAR subroutine to extract the elemental quantities and, i have prepared the script but not getting the output. But I am not getting it to work, can anyone suggest some tips or examples for that. Thanksthermal simulationMarc MentatPost Processingelevarhttps://community.cadence.com/cadence_technology_forums/physical-system-simulation/marc/f/marc/74214/vmap-standard-support/1432557Tue, 17 Feb 2026 12:40:00 GMT75bcbcf9-38a3-4e2e-b84b-26c8c46a9500:02656c9a-df64-4d21-a296-c68c2ccc12dfShank KulkarniThat is indeed a great suggestion. I will check with the team if there are any plans about it.https://community.cadence.com/cadence_technology_forums/physical-system-simulation/marc/f/marc/74214/vmap-standard-supportTue, 17 Feb 2026 03:03:00 GMT75bcbcf9-38a3-4e2e-b84b-26c8c46a9500:34cbb824-ee9d-42b5-b172-b84b4f096438Nils LangeDear Developers of MSC Marc, you are familiar with the VMAP Standard (vmap-standard.org) and worked with them in coorporation. Currently it is supported until Version v0.5.1. However you stopped developing for the standard (as I heard, because the respective programmers don't work for MSC anymore). I suppose it wouldn't be any difficult to start supporting the current Version v1.2.0 again, especially since it might only require very small changes. Are there any plans from your side for the future? Kind regards, Nils Langehttps://community.cadence.com/cadence_technology_forums/physical-system-simulation/marc/f/marc/74200/usinc-subroutine/1432529Tue, 03 Feb 2026 14:12:00 GMT75bcbcf9-38a3-4e2e-b84b-26c8c46a9500:fb327350-9034-4e0c-88fb-980f538f36ecShank KulkarniYou can use " Nodal Results Database Utility Routine" where you can get co-ordinates using node number. You can call it as call nodvar(35,nodeid,valno1,nqncomp,nqdatatype) here nodeid will be your node number and the code "35" relates to quantity you request. As shown in manual the code "0" should give you co ordinates. valno1 will be the variable where those co-ordinates will be saved. All the details can be found here: https://nexus.hexagon.com/documentationcenter/bundle/marc_2024.1/page/combined_book/vold/dch01/Nodal.Results.Database.Utility.Routine.xhtmlhttps://community.cadence.com/cadence_technology_forums/physical-system-simulation/marc/f/marc/74200/usinc-subroutineTue, 03 Feb 2026 09:32:00 GMT75bcbcf9-38a3-4e2e-b84b-26c8c46a9500:594744ec-5450-48b7-9a61-09cbfb1f4b39Daniele PellegriniI tried to use the USINC subroutine to assign a temperature field in a thermal stress analysis. My temperature field depends on the coordinates of the points, but I don't understand how it's possible to retrieve them, as USINC seems to be a function that operates only with the node number.https://community.cadence.com/cadence_technology_forums/physical-system-simulation/marc/f/marc/74192/mesh-connectivity-between-two-contact-bodies-for-thermal-analysis/1432518Mon, 26 Jan 2026 04:57:00 GMT75bcbcf9-38a3-4e2e-b84b-26c8c46a9500:09b82776-5535-477a-af1d-c1f11415b65dAyush SrivastavaThanks for your help.https://community.cadence.com/cadence_technology_forums/physical-system-simulation/marc/f/marc/74192/mesh-connectivity-between-two-contact-bodies-for-thermal-analysis/1432515Fri, 23 Jan 2026 04:48:00 GMT75bcbcf9-38a3-4e2e-b84b-26c8c46a9500:fcee1e65-397c-419a-b4af-db762c903aabKiranraj ShettyYes. you can use one part with varying mesh densities ( connectivity must be maintained) with different materials without defining contacts.https://community.cadence.com/cadence_technology_forums/physical-system-simulation/marc/f/marc/74192/mesh-connectivity-between-two-contact-bodies-for-thermal-analysis/1432513Fri, 23 Jan 2026 03:40:00 GMT75bcbcf9-38a3-4e2e-b84b-26c8c46a9500:4f3cd776-4beb-40b5-a7e5-962a06f59286Ayush SrivastavaHi Kiranraj, Thanks for the reply. I will try that. Just out of curiosity, is it possible to define a single body instead of two bodies and use fine mesh at the top, let's say for a few microns and use coarse mesh for the rest of the body. And for the fine mesh elements use different material material properties than the coarse mesh?https://community.cadence.com/cadence_technology_forums/physical-system-simulation/marc/f/marc/74192/mesh-connectivity-between-two-contact-bodies-for-thermal-analysis/1432512Fri, 23 Jan 2026 03:36:00 GMT75bcbcf9-38a3-4e2e-b84b-26c8c46a9500:8d0fad75-3f64-47fc-a05d-2ba0a188b6b1Ayush SrivastavaHi Amol, thank you for the suggestion. I will surely look at the example and try to apply it in my simulation.https://community.cadence.com/cadence_technology_forums/physical-system-simulation/marc/f/marc/74192/mesh-connectivity-between-two-contact-bodies-for-thermal-analysis/1432511Fri, 23 Jan 2026 00:20:00 GMT75bcbcf9-38a3-4e2e-b84b-26c8c46a9500:726b2cf0-09ac-4d18-b4e9-4963fc3b9f00Kiranraj ShettyHi Ayush, You can define Thermal Glue contact between the two contact bodies with "Temperature constraint" activated as shown in below image, to maintain constant temperature at the contact interface. If this option is deactivated, heat transfer by conduction takes place which is dependent on the " Contact Heat Transfer Coefficient". Contact HT coefficient is also used for Touching contact as explained in previous response. Regards, Kiranraj Shetty