Virtual simulation, real impact: CAE in the automotive industry

Born in India, mechanical engineer Prasanna Kondapalli moved to the United States close to four decades ago to pursue his postgraduate studies: a master’s and a Ph.D. degree from the University of Kentucky. Today, after 28 years working at BASF, he is considered one of the top Computer Aided Engineering (CAE) experts in BASF North America, with dozens of projects completed and tools developed. Learn more about his outstanding career below.

What is Computer Aided Engineering (CAE) and what is the importance of this tool for BASF?

CAE essentially involves using specific software to virtually simulate the behavior of materials, parts and assemblies under certain loads and boundary conditions. We want to basically simulate the actual behavior of a material and see how it'll function under certain scenarios. We use commercial software as well as solutions developed by our own BASF team, called Ultrasim^®.

Our work with CAE at BASF is crucial to show customers how our materials will perform in a specific application for their products. The customer, normally a supplier or an Original Equipment Manufacturer (OEM), require certain specifications and by means of CAE we can simulate the behavior of the material in their application and see if it meets their specifications.

Once the design is finalized through CAE, the customer develops the prototype and conducts physical tests. This initial work reduces costs significantly for customers because they don’t need to manufacture multiple prototypes to then test and discard or reformulate to meet specifications. If they can succeed in the first attempt during the physical testing, they can save thousands of dollars. Our aim is to directly move to production avoiding multiple iterations of prototyping.
 

What is your role at BASF?

I am a Senior CAE Specialist for Engineering Plastics, in the Performance Materials business. Our team is split between structural simulation and mold filling simulation, and I lead the structural team. We mostly support the automotive industry in addition to other BASF customers in the industrial sector.

Our team is also involved in metal to plastic conversions in the automobile industry, finding the best alternatives to aluminum and steel. These metals tend to make vehicles heavier, which leads to higher fuel consumption. The lighter the vehicle, the higher the fuel efficiency and the less CO₂ emissions it generates. That is one of the benefits of switching to plastic materials.

We analyze a wide range of structural mechanics areas such as statics, steady state dynamics and noise, vibration and harshness (NVH), transient dynamics (crash/impact) and long-term behavior such as creep, relaxation and fatigue (durability).

Additionally, we work with recycled materials which pose important challenges, since their properties are somewhat degraded. For this reason, we need to make sure the prediction is in line with the degraded properties and design suitability to meet specifications
 

What kind of tools have been developed by BASF to make simulations more accurate?

At BASF we use tools that were commercially developed, and others that were developed in-house to meet the needs of our customers and teams. Ultrasim^®, developed by colleagues in Germany 25 years ago and continuously being enhanced, is essentially a framework where we have developed highly advanced numerical models for our materials. In my opinion, Ultrasim^® provides almost unsurpassed accuracy compared to our competitors.

This development has made many of our applications possible. It’s a highly advanced tool where we are describing material behavior in a detailed fashion. There are two ways you can define the material, one of which is isotropic, which means the material has the same properties in all directions and the other one is an anisotropic (Ultrasim^®) approach where the properties are different in different directions. Some of our materials contain short glass fibers which are randomly oriented throughout the part. So we obtain the fiber orientation of these glass fibers from the injection molding process and map the material properties based on the fiber orientation to get a fully anisotropic material model. This advanced model predicts material behavior and failure much more accurately, and it’s one of our greatest strengths.

One of the tools we developed in 2000, during my initial years at BASF, was the burst failure index (BFI). At that time, we were working on air intake manifolds which regulate the flow of air-fuel mixture to the engine. This part was initially made from aluminum, and the plastic version was constructed by vibration welding two halves. However, with this welding method, the joint is often weaker than the parent material and is prone to failure.

The BFI is a tool to predict the strength of that vibration weld and is based on a series of experiments we did coupled with a mathematical model. Customers were impressed with its accuracy, and we were able to capture the bulk of the market’s intake manifold business. And this tool continues to be used today by the team and has been extended to other joining technologies such as laser welds, infrared (IR) welds.

What is the composite seatback project?

This project was developed between 2005 and 2010, and involved converting the traditional automobile seatback into a plastic one, which at the time was not available. This development was done in phases. Initially, we converted an off-the-shelf seatback to a plastic one with good success. This led to a collaboration with a seating company, to develop a fully composite front row seatback from scratch for the very first time.  

The seat was comprised of three different materials, mainly BASF’s short fiber reinforced PA6 polymer, continuous glass fiber tapes and metal in critical locations. Continuous fiber tapes were a new material for us, and we had to conduct extensive studies to develop material models for them. The short fiber PA6 was modeled using our Ultrasim® framework. 

The whole seat development was done virtually using CAE tools. The two main CAE simulations carried out were a rear crash simulation with a dummy and a frontal crash with luggage retention to ensure the integrity of the seat. After confirming the seatback met the requirements with CAE simulations, the prototype parts were made. The physical testing was next, and we were able to pass the tests in the first attempt without any modifications. This was definitely a feather in our cap.

This first composite seatback laid the foundation for our current work in seating with multiple projects with important OEMs. These seats can be adjusted and have been for the past few years. The metal seatbacks, which in some cases comprise of as many as 50 parts, can be consolidated into 3-4 parts for the plastic version. With plastic, we are able to simplify the seating and optimize mass use, keeping the material to a bare minimum, lowering the cost for our customers.




 

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