In the process, the later the design change occurs, the higher the cost of the change, especially for the architectural solution. The design plan needs to be done as soon as possible, while making more evaluation decisions; The development of vehicle bodies requires a large number of collaborative multidisciplinary constraints and boundaries. The later the process, the lower the flexibility of collaborative adjustment among various specialties. The collaboration between vehicle bodies and various specialties also requires early research to fully tap the potential of the solution.

　　On April 18-19, 2023, at the 3rd 2023 Body and Interior Decoration Conference. Xu Jianbin, Senior Advisor of Dassault Systems Industry Process, stated that a large amount of body development work has shifted to the concept development stage and has become a trend before, in order to evaluate, predict, discover and solve problems in advance, control development costs, and shorten the overall development cycle; The concept stage vehicle body has the characteristics of large adjustable design space and frequent changes in vehicle design. Traditional modeling and simulation techniques cannot respond quickly to the characteristics of the vehicle body concept design process. Through innovative MODSIM modeling and simulation integration technology, efficient development of the vehicle body concept stage can be supported, achieving rapid modeling, change evaluation, optimization, and selection of large-scale vehicle body concept solutions.

　　Xu Jianbin | Senior Advisor of Dassault System Industry Process

　　The following is a summary of the speech content:

　　MODSIM is a technology that integrates modeling and simulation with Dassault. How can this technology quickly improve the efficiency of early body development? The following will introduce to everyone from all directions.

　　Trends and Challenges in the Development of Conceptual Structures for Vehicle Bodies in the Early Stage

　　In the process of virtual development of car bodies, firstly, the later the design changes occur, the higher the cost of adjusting the architecture scheme. We need more design schemes to evaluate and make decisions as soon as possible.

　　Secondly, body development requires coordination of a large number of professional constraints and boundaries, and we interact with many general arrangements or designs. If a variety of multidisciplinary collaborative development is carried out in the early stage, the flexibility of adjustment will be relatively high, and the later the adjustment, the lower the flexibility. The collaboration between the vehicle body and various specialties requires early research to fully tap the potential of various early plans.

　　A large amount of body development work is gradually moving forward to the concept development stage, which has the advantage of being able to predict, identify, and solve problems in advance, shorten the development cycle, and control the final development cost.

　　As shown in the following figure, during the conceptual design phase, we first have the initial version of the virtual design model, and there will be many changes in the plan that require optimization of the architectural plan. Finally, we will proceed with detailed design after the conceptual design is frozen.

　　Source: Dassault System

　　The traditional process involves different departments and a lot of software switching and transmission, while the design and modeling methods are inefficient. The separation of modeling and simulation results in time-consuming and labor-intensive pre simulation processing work.

　　Under traditional modeling techniques, the conceptual model scheme of the vehicle body is not flexible enough, and in complex scheme changes, a large amount of manpower is required to model and modify the vehicle body structure, resulting in a longer design change cycle.

　　Meanwhile, traditional structural schemes require manual creation and do not achieve full parameterization, making it difficult to conduct rapid multidisciplinary performance verification. When the performance is finally gathered together, it will be found that there are many conflicts between the schemes, resulting in ineffective early design schemes; Non parametric models may also result in the inability to conduct further and deeper scheme optimization and exploration, but without a large amount of sufficient design and scheme iteration, there will be many design changes after entering detailed design, and the cost of changes will be very high.

　　Based on the above, we hope to move more work forward to the conceptual design stage.

　　Efficient development plan for the early conceptual structure of the Dassault system body

　　Dassault System has evolved from the earliest 3D design software to 3D DMU digital prototypes, to the PLM lifecycle, and now to the 3DEXPERIENCE integrated virtual twin collaborative development platform. Every decade, there is an innovation in technical concepts to assist in the digital transformation of the industry.

　　We have a complete set of solutions for the automotive industry, supporting the digital research and development of enterprises from the initial stage to the final mass production. Today, we mainly focus on the design of engineering structures, and here we help everyone understand the application of this technology through conceptual design.

　　Unlike the fragmented state of design and simulation in traditional methods, the integrated modeling and simulation technology of Dassault system seamlessly connects from design to simulation, and fully parameterizes the entire model to quickly adjust the model. The simulation model is automatically generated based on CAD models, which saves a lot of simulation preprocessing work and can achieve rapid scheme verification; Simultaneously parameterized patterns can be used for multidisciplinary performance verification and rapid simulation verification; Multi disciplinary performance optimization and lightweight optimization can also be carried out.

　　We can also make quick multi-disciplinary trade-off decisions for vehicle body indicators, achieve simulation driven design through rapid validation of simulation models, conduct large-scale simulation iterations in a shorter time, and optimize and design the driving structure. The CAD model itself is a CATIA model, which can also be used for early conceptual collaborative design, such as collaborating with the general layout and styling, and continuing with further in-depth design based on the CAD model. The process of detailed design can be followed by the CATIA model for subsequent engineering deepening design.

　　The development collaboration mode scheme of Dassault system allows design engineers and simulation engineers to achieve closer collaboration in conceptual design tasks based on this technology. Even some basic simulations, such as linear simulations, can be directly done by design engineers; If it involves high-level simulations such as collision and safety, the simulation model automatically generated based on CAD models can be directly transmitted to simulation engineers for rapid simulation solutions.

　　Overall, the new modeling approach can lead to more efficient generation of conceptual models, improving the efficiency and quality of conceptual design. The seamless integration of second modeling and simulation, with automatic generation of simulation preprocessing models, can improve the efficiency of performance verification with almost zero time consumption. Thirdly, we directly use the automatically generated simulation model to submit optimization calculations, allowing design engineers to easily conduct basic simulations and achieve fast iterations; High order simulation can directly use automatically generated simulation models, submit simulation optimization, and improve the validation efficiency of professional simulation.

　　After the process reaches the conceptual model change and verification stage, based on the fully parameterized model and MODSIM modeling and simulation integration technology, the design scheme can be quickly changed, the performance of the design scheme can be verified, and the verification efficiency, iteration efficiency, and decision-making efficiency can be improved. The parameter development model can also achieve the combination of optimization software and optimization platform for multi-disciplinary automatic optimization, fully exploring the combination of different parameters and schemes, and obtaining higher quality car body structures.

　　Application Cases of Dassault System MODSIM Technology

　　Currently, many customers are using the Dassault system MODSIM technology, mainly for preliminary concept development, multidisciplinary optimization, and lightweight work.

　　Mainly introduce the concept development process and ideas of Ford based on MODSIM technology. Ford has a department for early concept development, with architecture research in the early stages and a VCS process for virtual concept development.

　　Firstly, we will have a lot of data input, which can be CAD models, competitor vehicle data, or other historical vehicle model data. All data input will serve as a reference for the construction of early conceptual models. Conduct parameterized model construction for the local front cabin in the early stage, and study the multidisciplinary performance of the local model. Because Ford is based on platform based development, the concept development needs to first optimize the lower body and use alternative models or shapes to develop the upper body.

　　Through MODSIM technology, a CAD model was established earlier, and after the CAD model was established, the simulation model was automatically generated; Through this technology, the multidisciplinary performance of different structural schemes can be quickly verified. Including safety related frontal and side impacts, as well as stiffness modes. Why are these performances? Because these properties are related to the frame structure of the vehicle body, and strength is more of a local performance, frame performance is more defined in the conceptual stage. In short, if there are any issues with these performance models, it will be difficult to achieve results through local structural changes during the detailed design stage. Therefore, we hope to optimize these performance models as soon as possible, in order to optimize a better body framework.

　　The preliminary work of VCS formal concept development is the development of local models. After the previous optimization, we officially entered virtual concept development and conducted multiple rounds of optimization iterations using MODSIM technology.

　　Firstly, there will be three schemes for the lower body, where the upper body will be simulated using similar shapes or structures to concentrate on optimizing the lower body platform. With three MODSIM CAD models, it is possible to quickly evaluate multidisciplinary performance. After the first round of evaluation is completed, we can gradually reduce the number of targets for evaluating the vehicle body plan, and ultimately select or freeze the conceptual plan for the vehicle body.

　　After the concept of the car body was frozen, the car body entered into detailed body design and engineering development; The upper body enters the development of a series of vehicle models, and then continues to use MODSIM technology, similar to dolls, to combine different conceptual models of the upper body MODSIM with existing models of the lower body for vehicle level optimization.

　　Through MODSIM technology, Ford was able to conduct multidisciplinary optimization, lightweight, and rapid multi-platform development of early concepts in the early stages.

　　In summary, the integrated technology of MODSIM modeling and simulation can improve the efficiency of body engineering, conceptual and detailed structural design in the early stages; In the early stages of the process, it is also possible to intervene in vehicle level performance evaluation and optimization, improve early development efficiency, and shorten the research and development cycle. At the same time, a large number of performance iterations and solution iterations can be carried out to improve understanding of the body structure and improve the quality of body products.

　　(The above content is from Xu Jianbin, Senior Advisor of Dassault Systems Industry Process, who delivered a keynote speech on "Efficient Development of MODSIM Drive Body Pre Concept Structure" at the 3rd 2023 Body and Interior Decoration Conference from April 18-19, 2023.)