LS-DYNA

LS-DYNA is a Finite Element Analysis (FEA) solver developed to simulate highly dynamic, inelastic, large deformation problems. It is widely used in the automotive, aerospace, military, and other engineering fields for multifaceted dynamic applications. Elmore Engineering's employees have experience using LS-DYNA to solve problems involving blast analysis, vehicle impact analysis, and other dynamic engineering problems. We have also used LS-DYNA to verify and/or evaluate the performance of structural components and systems.

LS-DYNA Capabilities:

Featured Projects

Explosive Effects

Our client required the protection of an underground piping system from a surface blast overpressure. Key to this evaluation was not redesigning the piping system depth and separation. EESI's engineering team used an LS-DYNA Arbitrary Lagrangian Eulerian (ALE) analysis to determine shockwave propagation through the soil medium and obtain the resulting blast loading on the underground piping. Once the loading was determined a structural analysis of the pipe was performed to determine damage caused by the overpressure.

Vehicle Barrier Design

Our client needed to maintain an aesthetic line of K12 bollards in a new construction project. However, maintaining that line meant the bollards would be placed along the edge of a sunken courtyard. Our task was to create a never before designed foundation system that maintained a K12 rating and zero vehicle penetration. EESI's engineering team performed iterative LS-DYNA vehicle impact simulations to develop and optimize a robust bollard system and foundations while maintaining a desired architectural aesthetic and crash ratings.

Blast Analysis

Our client wanted to know the damage that would be caused by an explosive charge detonating near a structure and more importantly if critical components inside would survive the explosion. EESI's engineering team developed an LS-DYNA Arbitrary Lagrangian Eulerian (ALE) model of the structure to perform an analysis that determined shockwave propagation through air and water medium thus determining the blast loading effects on the structure and critical components.

Vehicle Impact Analysis

Installation of new swing gates to update physical security proved challenging at a location where adequate soil was not provided. The sides of the subgrade foundations would potentially be exposed to existing slopes. The swing gate needed to be rated for NRC specific requirements. EESI's engineering team performed LS-DYNA vehicle impact simulations to determine any vehicle impact penetration. The results of the simulations were shown to be favorable and the grade did not affect crashworthiness.

Vehicle Impact Analysis

As part of physical security upgrades at a nuclear site, the client was installing new crash rated vehicle gates. The selected gate was a Delta Scientific DSC7500 model. These gates needed to be evaluated to ensure they meet NRC requirements for a Design Basis Threat (DBT) vehicle load. EESI's engineering team worked with Delta Scientific to develop an LS-DYNA Finite Element Model and performed an analysis of the new vehicle gate and the primary structural components. The gate was subjected to the DBT vehicle impact load and was shown to perform favorably, with near negligible vehicle penetration.

MSSD Determination

Our client was interested in determining the minimum safe standoff distance for a trussed roof when subjected to a DBT vehicle explosive charge. EESI's engineering team built an LS-DYNA finite element model of the critical roof truss and using that model simulated the side-on pressure explosive effects. Using that simulation EESI identified and reported potential concerns and made recommendations for the minimum safe standoff distance to the structure.

Confined Explosion Analysis

Our nuclear power plant client was posed with the scenario of a hand carried explosive being detonated in a critical room. This required an interior explosion simulation to determine potential blast effects on the confining structure. Due to the highly complex behavior attributed to confined explosion, EESI's engineering team utilized Finite Element Solver, LS-DYNA Arbitrary Lagrangian Eulerian (ALE) methods to simulate the blast propagation of the room. Structural damage was approximated by using these blast profiles to perform dynamic, elasto-plastic analyses on on the room's structural elements. The critical room was determined to survive the event and maintain functionality.

Stress Analysis

Our nuclear client requested a higher fidelity evaluation be performed for a Residual Heat Removal (RHR) Weldolet connection. Traditional methods of evaluating the piping stress were resulting in exceedance of code allowable stresses. EESI performed a more refined approach to evaluate the RHR Weldolet using LS-DYNA Finite Element Analysis Software. Code based load combination were applied to the location and resulting stresses were shown to be less than the allowable values thus remaining in compliance.