An Example for SPH Model

Description

Before explaining what the SPH model is, we might need some background knowledge.

Abaqus:

Abaqus is an FEA software to analyze models with high complexity. The provided option by this software creates a great environment to study various models. Not even solid mechanics but also thermal and fluid mechanic models can be simulated in this software. It is worth to mention the fluid mechanic model was separated after Abaqus 6.16 and since version 2017 the company started to develop an independent solver for it.

There are two types of simulations in Abaqus to simulate a process which are 1- Implicit 2-Explicit model. Implicit models are helpful in simulating a process close to a steady-state. On the other hand, Explicit models are good to simulate fast models with element deletion. The damage model is one of the explicit models. Damage models are commonly used to simulate part failure and are only possible with the explicit method.

Explicit Vs Implicite models:

Here we explain the differences between explicit and implicit models to avoid any confusion between these two and the SPH model.

Implicit models:

Because implicit models have larger time increments they can be modeled with a larger step time. This advantage allows you to create models that require a longer time in the real process. This is because of the element formulations used in this technique. The most common examples of implicit models are rolling processes, low deformation processes and satellite movements in space. However, there are problems which make it impossible to use implicit models for some processes. Models that require sudden change and large deformation, it is necessary to use a small time increment size. Since the required time to solve each increment is large, it is not affordable to create models with numerous increments. Consequently, implicit models are not good for models like simulating explosions and some types of forging.

Explicit models:

Explicit models have smaller time increments compared to implicit models. In fact, explicit models are the combination of lots of static models to minimize the effect of acceleration in simulation. The time increments are small enough to ignore the effect of acceleration in each increment. However, the effect of acceleration excites in the whole process. Since the time increments are small, it is possible to create models with large deformations and sudden changes. The most common examples of explicit models are explosions, large deformation processes, and models with complex surface contacts.

Use this product if you would like to learn more about explicit models:

SPH models:

Smoothed particle hydrodynamics (SPH) is a method to simulate extreme large deformation such as simulating water or gas material. SPH model is a mesh-free method that is common for the mechanics of continuum media. It is also very helpful for fluid-structure interaction (FSI) models. The FSI can be found in many natural phenomena, such as birds flying and fish swimming. Meanwhile, it also plays an important role in the design of many engineering systems, e.g., aircraft, engines and bridges. Although the mechanical behaviours of the FSI systems are quite different, their common essentials are structures and internal or external fluid flows [1]. Since FSI problems usually involve nonlinear fluid and solid dynamics, which are complex to solve analytically, they mostly have to be analyzed by means of experiments or numerical simulations. The individual maturity of computational dynamics (SFD) and computational solid dynamics (CSD) in past decades enable it [2-3].

About this product:

In this example, we simulate a volume of water that crushes a plate with high speed. We can also use this model to simulate a bird crushing a plane to see the plate response after impact. We only give one example to help you use the SPH model. In this video, we avoid giving too many details so you can easily use the product and learn how to use this option in Abaqus to simulate super large deformation processes. In this product you can find the following files:

Abaqus files: CAE, ODB, INP, and JNL

Solidwork model

Powerpoint files that contain more details.

Video files: How to create this model, Powerpoint presentation.

For more information please send me an Email:

rezatangestani@hyperlyceum.com

[1] Bungartz H. J., Schäfer M. Fluid-structure interaction. Modelling, simulation, optimisation [M]. Berlin, Heidelberg, Germany: Springer Science and Business Media, 2006.
[2] Sigrist J. F. Fluid-structure interaction: An introduction to finite element coupling [J]. Computers and Mathematics with Applications, 2015, 69(10): 1167-1188.

[3] Han, L., Hu, X. SPH modelling of fluid-structure interaction. J Hydrodyn 30, 62–69 (2018). https://doi.org/10.1007/s42241-018-0006-9