The Incompressible Smooth Particle Galerkin (ISPG) theory was proposed by the R&D team Computational and Multi-scale Mechanics Group (CMMG) at LSTC in 2017 [1]. It developed a new Incompressible Navier-Stokes solver to model free-surface Newtonian and Non-Newtonian fluid flow with surface tension and adhesion force. The Lagrangian particle method was employed to discretize the ISPG part to approximate the Navier-Stokes equation, coupled with surrounding rigid structures. The ISPG method is fully implicit, and in its dynamic mode, it simulates in real time fluid behaviors in many manufacturing processes. The ISPG’s robust, in-core, and smart mesh adaptivity allows fluid flow in complex geometry, accurately capturing and aligning the ISPG surfaces with the structure surfaces while keeping the model size down. It also allows for separation and fusion within the ISPG fluid. The ISPG advanced material models allow for the simulation of fluid behavior with various viscosities from liquid to near solid state.
With an increased use of aluminum in automotive body structures, developing a deep understanding, and capability to model failure of aluminum resistance spotwelds (RSWs) is critical [1]. This paper discusses failure card development of aluminum RSWs using LS-DYNA for certain 5000 and 6000 series flat rolled sheet alloys used in automotive structural applications.
One of the challenges in modeling deflagration of solid propellants with LS-DYNA is its limited capability, which is mostly applicable to airbag systems that use gaseous nitrogen generated by burning sodium azide. To overcome this limitation and enable the modeling of custom propellant grains with specific geometries, perforations, surface inhibitors, impetus, burn rates, and co-volumes, a user-defined burn model must be defined. In this study, a custom internal ballistic analysis code is integrated into LS-DYNA to simulate kinematic systems driven by pyro-mechanical devices such as pyro pushers, cutters, thrusters, separations bolts, ejection seat catapults, etc. Step-by-step guidance is provided on implementing a user-defined loading subroutine and the requirements for compiling a custom LS-DYNA executable along with a simple pyro thruster example.
The evolution of automotive safety systems has witnessed a remarkable journey over the past few decades, with airbags emerging as pivotal components in mitigating the severity of injuries during vehicle collisions. Initially conceived as relatively simple passive restraint systems, airbags have undergone a profound complexification in their design and functionality, driven by the relentless pursuit of enhanced occupant protection and regulatory compliance. Today, modern vehicles incorporate a diverse array of airbags strategically positioned throughout the cabin to address various collision scenarios. From front and side airbags to curtain and knee airbags, this proliferation underscores the nuanced approach to occupant protection adopted by automotive manufacturers.
Application of the ISPG Method in Various Manufacturing Processes Simulation