Extract from XTech Media, September 21st (Japanese version)
Mazda's "integrated planning" confident of success in EVs Reduces man-hours with simulation-driven car body design
Significant reductions in development man-hours and costs have been realized through "batch planning," which shares the car development concept for all vehicle models, and through Model Based Development (MBD), which utilizes simulation to minimize the need for actual vehicle verification. Mazda did. For example, the low fuel consumption, high compression ratio engine ``SKYACTIV'' announced in 2010 is one of the technologies that symbolizes the success of the company's innovative development methods.
MBD's achievements are not limited to engine development. In the area of vehicle body development, the development philosophy of integrated planning and the MBD development process have created a synergistic effect, increasing development efficiency in body frame studies. We asked engineers from the Body Development Department of the company's vehicle development headquarters about the current body development process and efforts toward electrification of cars (Figure 1 ) .
Figure 1: Engineers from the Body Development Department, Mazda Vehicle Development Headquarters
From left: Mr. Hidenori Nagaki of the Body CAD Group, Mr. Chie Matsuoka and Mr. Isamu Kizaki of the Body Advanced Technology Development Group. (Photo: Nikkei Manufacturing)
Push performance verification upstream in the process
Surprisingly, Mazda's body development efforts have increased the efficiency of body frame studies by adding one step to the development process ( Figure 2 ). Specifically, before designing a detailed car model using 3D-CAD, a rough structural model for CAE analysis is created. Based on this model, we repeatedly verified its performance and decided on a body framework that was as close to the optimal shape as possible before moving on to detailed design. This is a development process called "simulation-driven design."
Figure 2 Overview of Mazda's body development process
In the current development process, a rough structural model for CAE analysis is created before creating a detailed model using 3D-CAD (see the diagram above). Based on this model, we used the simulation-driven analysis tool "CATIA SFE CONCEPT'' to repeatedly change the shape and perform CAE analysis in rapid cycles to determine the body skeleton. On the other hand, in the past, detailed models were created from the beginning, relying on the experience and intuition of engineers (see the figure below). CAE analysis based on detailed models requires a lot of time to generate meshes every time a design is changed, which is a factor that delays development.
(Source: Created by Nikkei Monozukuri based on Mazda materials)
In the conventional development process, the structure to obtain the desired body characteristics was created using 3D-CAD from the beginning. Parameters such as the thickness and length of parts were determined "mainly by past experience and intuition'' (Isamu Kizaki of the Body Advanced Technology Development Group of the Body Development Department). Once the detailed model is completed, we run simulations using CAE and repeat performance verification and design changes.
At first glance, it seems that the current process requires more CAE analysis before detailed design, which increases development man-hours, but in reality, a major bottleneck in the conventional process has been resolved. The bottleneck is the time required to generate a finite element model (mesh) for CAE.
The more complex the model, the more difficult it is to generate a mesh. The conventional process of performing CAE analysis multiple times using a detailed model required a great deal of effort to generate a mesh each time a design was changed. Because the company's design and analysis departments are separated, the amount of time spent communicating requests for analysis and feedback on results was a factor that delayed development.
