Simulation Structure-Structure Interaction Many Boxes

In this article, we present a structure-structure interaction (SSI) simulation between falling boxes. The blocks or boxes are not stored stably, so they start to fall. All boxes/blocks behave like rigid bodies and the collisions are completely inelastic. This is referred to as a so-called rigid body simulation (RBS).
The boxes are modeled as rigid bodies and are free to move unconstrained when forces act on them. The individual rigid bodies can collide with each other and can change their direction of movement. The collisions between the rigid bodies and the walls are assumed to be completely inelastic collisions in this study. An inelastic collision, unlike an elastic collision, is a collision in which kinetic energy is not conserved due to the effect of internal friction. The NOGRID software can compute both collision regimes controlled by a plasticity coefficient.

Figure 1: CAD groups created in NOGRID's COMPASS

SSI many boxes case setup within NOGRID points CFD software's GUI

Figure 2: Setup the SSI Many Boxes Case

SSI many boxes - simulation results in NOGRID points CFD software's GUI

Figure 3: Result view of the SSI case within NOGRID points' GUI

Animation SSI many boxes case in NOGRID points CFD software

Figure 4: Animation SSI interaction many boxes

Rigid body simulation referts to the simulation of the transient motion of rigid bodies. Rigid body mechanics deals with physical bodies that are assumed to be non-deformable. During the simulation, the rigid bodies can move, but their shape or structure remains unchanged. Various types of forces may act on a rigid body: gravity, magnetic forces, frictional forces, etc. These forces accelerate the rigid body, causing changes in its translational and rotational velocities. In addition, collisions between rigid bodies may occur, which result in sudden changes in the translational and rotational velocities of the bodies involved.

In this 3D example, several boxes fall and interact with each other (see Figures 1 - 4). The simulation is solved in a fully coupled manner using the Lagrangian method. Fully coupled means that the stresses within the bodies are simultaneously resolved in a large solution matrix. Alternatively, the Eulerian method can also be applied to solve this case.

As with any rigid body in FSI coupling, the boxes in this simulation are assigned a weight and a mass moment of inertia. Each rigid body therefore responds to the forces acting on it. When several rigid bodies are involved, the motion of one body may also be influenced by collisions with others.

NOGRID points can be effectively used for design and problem solving for all kinds of FSI processes. The software helps to understand the flow by computing and visualizing the mass, momentum, and motion of single or multiple rigid bodies. It provides transient values that can be used to analyze and evaluate the efficiency of components and processes.

Capabilities of NOGRID points CFD software

NOGRID combines abilities to handle free surface flow and moving parts in the domain and allows the simulation of any conceivable geometry and operating modes such as

computation is in full 3D solving complete Navier-Stokes-Equations
easy and intuitive setup also for SSI (Structure-Structure Interaction) cases
free definable material properties by equations or curves
evaluation of chemical reactions and corresponding heat source terms
open or closed domains including inflow and outflow areas (non-batch mode)
moving of parts

Whitepaper Nogrid points Technology

Nogrid's strengths

Particular strengths of NOGRID's fluid flow CFD software are the rapid preprocessing (no fluid grid needs to be generated, only the boundary mesh, inner finite points are generated automatically depending on User setting initially and during computation), and the outstandingly short computation time even for complicated cavities.

As you can see in the image below, the boundary of the geometry still requires a mesh to allow the interior finite points to detect the boundary. The boundary must therefore be meshed and the finite points inside are automatically generated during the simulation controlled by User specifications.

Easy and fast modelling: Build geometry, mesh boundary, setup the case and start computation

What is CFD from NOGRID?

CFD solves the fundamental equations that define the fluid flow process. With CFD software from NOGRID every engineer makes better decisions by predicting, analyzing and controlling fluid flow, heat and mass transfer or chemical reaction. By using NOGRID software for flow modeling you receive information on essential flow characteristics as for example flow distribution. Using it additional to testing and experimentation NOGRID software helps to improve the evaluation of your design – resulting in better construction and operation parameters, increasing planning security and money savings due to faster time to the marketplace for your product or process.

Choose NOGRID

With NOGRID, you choose professional CFD software and services – our aim is helping you to be successful. When you decide to work with NOGRID you choose close cooperation with a dynamic, flat hierarchies-organization. Short information channels result in quick and accurate professional support and service. Our team consists of highly qualified employees, who are experts in fields such as numerical simulation or computational fluid dynamics. Based on our know-how, we are pleased to offer the following services, responding to your individual requirements:

TRAINING

In our two-days training courses you will learn, how to use NOGRID CFD software efficiently. Our technical support team will teach you how to handle and solve different cases.

For more details please refer to Training Courses →

Technical Support

We offer full professional support from the minute you start using our software, by telephone or by email. Contact us, when ever needed.

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Service

Lack of time or resources and other constraints often make outsourcing an attractive solution. We help you with your flow modeling needs. Based on our engineering expertise in this field we offer individual numerical simulation services matching the unique needs of your organization.

For more details please refer to Simulation Services →