A Detailed Introduction to LS-Dyna for Structural Analysis

discover ls-dyna's pre post workflow for preprocessing and postprocessing, including geometry cleanup, element selection, property and material definition, boundary conditions, and solver-driven outputs.

Download and install LS-PrePost and Notepad++ from the official website, selecting a Windows 64 version above four. Run LS-PrePost 4.9 after installation and explore the interface in the upcoming session.

Learn to interact with the LS-Dyna model by rotating, panning, zooming, and changing rotation center, including auto center, using keyword files and useful shortcuts.

Explore how to interact with the LS-Dyna model by changing views and orientations, using the triad, and switching between isometric, top, front, and side perspectives to understand model geometry.

Explore the post and pre post graphical user interface, including the title bar, menu bar, model hierarchy, keyword manager, and view controls, to navigate geometry, mesh, and parts.

Explore working with ls-dyna pre post: manage files through new, open, import, save options, and update results with post processing tools like binary plots, d3 plots, and time series.

Explore the miscellaneous and view tabs in LS-Dyna to inspect model information, verify geometry, and switch display modes from shaded to wireframe.

Create ls-dyna section views using section mode or section plane, define planes, save them, and view animated cuts to inspect penetration, alignment, and contacts.

Use assembly and select part in ls-dyna to hide or show subsystems and parts, switch to wireframe or color presentation, and inspect section and material ids.

Learn how to select nodes and elements in LS-Dyna for structural analysis using area, polyline, circle, spear, proximity, and bypass options.

Demonstrates running a simple ls-dyna simulation for a 100x100x3 mm steel plate, using pre post, boundary conditions, shell elements, and measuring stresses and energy over 60 ms.

Explore the structure of an LS-Dyna keyword file, including star keywords, comments, and end markers, and learn to define elastic materials, shell and solid elements, and binary output.

Explore the standard (short) and long formats of LS-Dyna keyword files, including field lengths, formatting rules, and how to export and save with appropriate spacing.

Explore keyword arrangement for ls-dyna nodes and elements, including star node and star element syntax, node coordinates, constraints, and part IDs with normals.

Explore keyword arrangement for parts, sections, and materials in LS-Dyna, mapping IDs with star part, star section, star mat, and material properties.

Download ls-dyna manuals, including volume one keyword manual and volume two material model, to access start sections, codes, and material definitions.

Learn to model a 1 m cube under uniform top pressure in ls-dyna by converting pressure to a surface load, applying a load segment, and enforcing ground boundary conditions.

Explore the LS-Dyna database and control setup, including binary and ASCII outputs, D3 plot generation, and energy monitoring via post-processing.

Explore keyword arrangement for boundary and constraints in LS-Dyna, including star boundary, prescribed motion set, lcd, vat, and constraint nodal rigid body spc to apply boundary conditions.

Understand material nonlinearity in structural analysis with LS-Dyna, tracing elastic and plastic behavior from yield point to permanent deformation, and compare nonlinear elastic, elastic-plastic, bi-linear, multi-linear hardening, and hyperelastic models.

Convert engineering stress–strain to true stress–strain, compute plastic strain, and prepare Abaqus-ready data using star elastic and star plastic cards.

Learn how to define the MAT024 piecewise linear plasticity model with sigma y and the tangent modulus E ten. Convert engineering to true stress and strain, and compute plastic strain.

Conduct a displacement-controlled ls-dyna tensile test with 300 MPa yield and 18% ductility; compare true stress and plastic strain with effective plastic strain and yield stress for consistency.

Examine how the zero 24 field parameter and the fail parameter control plasticity in LS-Dyna’s piecewise linear model, including element deletion and data-driven material options.

Explore the MAT 018 power-law plasticity model, defining elastic-plastic behavior with isotropic hardening using K and n, plus optional sigma y and strain-rate parameters.

learn how to use the enclosed include file structure to combine control cards, materials, and mesh into a main file for integrated results.

Explore the include file structure for a full vehicle LS-Dyna model, tracing from the baseline to versioned subsystems using start include and relative paths (instrumentation, suspension, powertrain).

Explore hourglass, a zero-energy deformation mode in explicit LS-Dyna analysis, showing zigzag patterns and no stiffness, and learn how to avoid it with hourglass control and verification.

Demonstrate hourglass behavior in a shell element using a fuse plate example, showing how reduced integration causes hourglass energy and how fully integrated form 16 (or form 6) prevents it.

Learn to apply hourglass control in ls-dyna with HQ1, HQ4, or HQ6 to reduce distortion in reduced integration elements, verify results, and explore global versus local settings.

Learn how explicit LS-Dyna uses timestamps to resolve dynamic events with small time steps, governed by a stability condition that delta t equals Lc over sqrt(E/rho).

Explore the explicit analysis workflow, showing how a node force drives acceleration, displacement, strain, and stress through time steps under the CFL condition.

The session introduces LS-Dyna contacts, explaining why contact definitions prevent penetration and enable force transfer between components, how contact is detected, and how node-to-node connections compare to true contact.

Explore penalty-based and constraint-based contacts in LS-DYNA, focusing on master and slave surfaces, numerical penalties, and how penetration, stiffness, and friction govern contact behavior.

Explore contact definitions in LS-DYNA, distinguishing one-way and two-way, automatic and non automatic contacts, with penetration checks on slave and master surfaces and implications for computation time.

Compare automatic and non automatic surface-to-surface contact in LS-Dyna, verify contact behavior, and observe frictionless versus frictional sliding using prepared decks, output requests, and post-processing.

Learn node to surface contact in LS-DYNA, define slave and master surfaces, create set segments, apply initial velocity, and assess how area and density affect penetration.

Model spot welds with beam element type nine and mat 100, linking two parts via BIM element, and apply boundary conditions and a 100 N force to analyze load transfer.

Learn how to model spot weld failure in ls-dyna, using time-based and force-based criteria (axial, shear, and resultant forces) with an example at 5000 newtons and 60 milliseconds.

Explore creating a spot weld between two parts in ls-dyna using start constraint spot and start constraint generalized spot, including setting normal and shear failure criteria and viewing results.

Learn to model a spot weld with a solid hexa element in LS-DYNA. Create and detach the element, and define solid contact between top and bottom parts.

Explore implicit analysis in ls-dyna, tracing its history from explicit code to implicit capabilities and outlining load, step, memory allocation, and static and nonlinear applications.

Understand the implicit analysis workflow in ls-dyna with a simple bracket example, detailing memory allocation, the implicit general card, item flag settings, and multiple steps with convergence criteria.

Use load steps in implicit analysis to apply force incrementally, ensuring convergence while updating the stiffness matrix for nonlinearity and contact.

Explore memory allocation strategies in LS-DYNA's implicit analysis, comparing SNP and MPP, and learn how to allocate memory in million words for single and double precision across CPUs.

Discover essential keywords for implicit LS-Dyna analysis, including control implicit general, load step control, linear and nonlinear solvers, and implicit dynamic and eigenvalue options.

Guide configuring implicit auto controls in ls-dyna, manage timestamp size and time steps, and apply determine, max, it opt, and ITV for stable convergence.

Master implicit ls-dyna analysis by configuring linear vs nonlinear solvers with n solver, i limit, max, and convergence criteria, including norm and dc tall for displacement, energy, and force.

Perform modal analysis, or frequency analysis, to identify natural frequencies and mode shapes, then use free-free analysis to locate resonant risks and verify assembly connections.

Derive the governing equation for modal analysis in a free–free system, showing eigenvalue k/m and ω = sqrt(k/m), with density, Young's modulus, and Poisson ratio defining mass and stiffness.

Perform plate modal analysis in LS-Dyna by running free-free and boundary-condition cases and extracting eigenvalues. Inspect rigid-body modes, mode shapes, and the impact of boundary conditions on frequencies.

Demonstrates ANSA deck preparation for an LS-DYNA plate simulation: define material, thickness, boundary conditions, displacement curve, outputs, and run a 60 ms analysis.

Prepare ANSA deck for a 1 m cube under 100 mega particle pressure in NZ, define solid element form and material, apply bottom spc and load segment pressure, then run.

Prepare a non linear tensile test deck in ansa for ls-dyna using mat 24 piecewise linear plasticity and define starter database history to request l out data.

Apply global and local hourglass control in ansa deck preparation, enable hourglass energy in the energy card, and assign hourglass to fuse plate components for explicit ls-dyna analysis.

Prepare an LS-DYNA deck in Hyper Mesh for a 3 mm steel plate with a fixed end and a 5 mm displacement over 60 ms, including material and boundary setup.

Prepare an Ls-dyna deck in hyper mesh for a cube under 100 MPa pressure, using a star load segment set and boundary conditions, with a one-second dynamic run.

define a mat 24 piecewise plasticity model for a tensile test specimen in hypermesh, specifying yield strength 300 mpa and e ten 688, with database cloud and history shell outputs.

Learn to create spot welds and apply local and global hourglass control in HyperMesh for ls-dyna, including setting up loads, curves, and node-to-node connections.