If you look at Automotive Suspension Design and Development, the challenges are obvious. Two major departments look at completely different aspects of development. While the Vehicle Dynamics department focuses on delivering better ride handling characteristics, the Durability group focuses on delivering light weight design with desired fatigue life.

We asked Ravishankar Mariayyah, Solution Consultant with SIMULIA who developed this workflow, to provide answers to some common questions.

Q. Why does this workflow need to be analyzed?

A. This workflow illustrates the tremendous value that collaboration brings to design and development. Even though both groups use completely different CAE tools and processes, the system is the same, i.e. suspension assembly. Lack of collaboration between these group leads to error prone design and no opportunity to look at design iterations in a given design cycle time. This is due to non-systematic and manual data transfer between the two groups. Addressing this problem requires both teams to work in a collaborative environment so that they can shift their focus on a design and development set up that is automated and fully integrated. In this workflow we demonstrate how to achieve such a seamless collaboration by leveraging SIMULIA’s Power of Portfolio.

Q. Describe the workflow.

A. This particular workflow focuses on creating an automated template for suspension design and development. It is predominantly applicable to the automotive industry. The workflow involves setting up Simpack and Abaqus co-simulation in a fully automated way. Multi Body Systems (MBS) analyses of the suspension assembly is accomplished using Simpack.

With Simpack simulation of large number of system level load cases can be achieved in a much shorter time frame with reasonable accuracy compared to a full scale FE Analysis. It is feasible to analyze only a few critical components for durability such as Lower Control Arm (LCA) with a FE analysis suite such as Abaqus because of analysis time limitations. In addition, the part that is to be analyzed with Abaqus requires accurate forces input from the other parts of the suspension assembly for realistic estimation of stresses and strains. These forces are provided through Simpack MBS analyses.

Real time exchange of data eliminates the need for manual post processing with the output forces from Simpack analysis and manual pre-processing of the Abaqus model. The whole process gets automated by saving considerable amount of time. During the Co-Simulation each solver solves its sub-domain using its numerical technique controlled by SIMULIA’s Co-Simulation engine (CSE). Both Simpack and Abaqus output files are generated at the end of the Co-Simulation run.

The generated Abaqus .odb file is input into fe-safe for further fatigue analyses estimating the life of the LCA with acquired signals for combined loading of motorway and country road as input loading for fesafe. A fully integrated and automated process flow starting from Simpack MBS model to fe-safe fatigue analysis is then created in Isight environment for further design exploration using techniques such as DOE, Approximations and Optimization.

Q. What are you trying to learn from this simulation?

A. The overall objective of the simulation is to deliver the design of LCA for a target design life in a fully integrated and automated set up. The design variables, i.e. the inputs, can be either from Simpack or Abaqus and the output variable of interest is from the durability tool fe-safe. This way an end-to-end solution with simultaneous consideration of design requirements from the two major departments, i.e. Ride handling and Durability, is obtained.

Q. Which SIMULIA solutions did you use?

A. This workflow leveraged the following products:

• Simpack was used for multi-body system analyses.
• Abaqus was used for finite element analysis.
• fe-safe for fatigue life estimation.

These three products were also integrated within the Isight framework.

A. What were the benefits of using simulation?

Q. Simulation, especially in an automated and integrated set up, opens up possibilities of exploring design alternatives rapidly. It also helps to deliver innovative and high quality design solutions through a well-defined scientific approach. This leads to significant reduction in design cycle time there by bringing down design and development costs. This would also help organizations to reach the market earlier than competitors in addition to other valuable benefits such as increase in confidence of product performance and customer satisfaction.