Many design targets must be achieved before commercial vehicles such as trucks and buses are released to the market. An optimal design is one that best balances the many competing project targets, such as performance, regulator, ergonomics, time to market, cost, warranty and others. Exploring potential design alternatives by building and testing physical prototypes is extremely time-consuming and costly. Instead, Ashok Leyland Engineers use Multibody Dynamics (MBD), durability, crash and safety, Computational Fluid Dynamics (CFD), and Noise Vibration Harshness (NVH) simulation tools to evaluate the performance of a wide range of design alternatives. After identifying the optimal virtual designs that meet the design targets, engineers move forward to build and validate the vehicle for launch. This approach reduces engineering expenses, accelerates delivery to market, and meets or exceeds customer requirements.
With CAE driving the design process at Ashok Leyland, the types of simulations performed as part of the vehicle development process is growing rapidly. Multiple simulation tools are required to address each of the different domains involved in vehicle development. Each tool requires a fairly complex process in which the user develops a model, inputs various engineering data, performs an analysis, reviews the results and authors a report to support design decisions. Ashok Leyland previously automated some of these steps for a few simulation tools using macros and scripts, but these point solutions were difficult to ensure the usage and maintain. The previous process relied upon the skills of the individual analysts writing the scripts. These automations were not always shared, versioned or used consistently among engineering groups, resulting in inconsistent results from one analyst to another and lacked traceability. The lack of a common simulation structure meant that it was difficult to locate the results and understand the reasons for previous decisions, so work often had to be duplicated.
Ashok Leyland implemented MSC’s simulation process and data management (SPDM) tool to manage the complete simulation process from project initiation through final report generation within the CAE department. They were able to automate many tasks related to pre-processing, solving and post-processing using products from MSC Software, third-party vendors and custom Perl and Tcl scripts. This process has improved productivity, improved results consistency and traceability by automating the simulation process and providing a common user interface across all simulation domains. For example, engineers can generate an input deck for a frame analysis by selecting the configuration, such as 4×2, 4×4, or 6×2, and the application, such as a 1 man-day for individual components per iteration. Similar time savings have been achieved with other analysis tasks, as summarized in the table. As multiple iterations are required to develop a new product, very significant time savings are achieved in the product development cycle.
With respect to the savings for the overall activities of the CAE across all the domains, there is a realization of savings of 15% on Preprocessing, 80% in post-processing in Crash, CFD, Durability and NVH with the automation implemented using SPDM. About 60% savings in human effort is achieved in durability studies.