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processes are intended to be integral parts of the OEM standard vehicle development processes.
Altair addresses the above-mentioned challenges of vehicle level simulation driven design by:
1) providingprocesseswhicharecontrolled from efficient user interfaces to manage complexity,
2) usingabstractionlevelsforsimulation models adopted to allow in-time and relevant design feedback,
3) implementingnewmethodsand technology to reduce time for simulations/ optimizations, and
4) byusingahighlevelofautomationand standardization of processes
The two most significant Altair simulation driven design processes for vehicle, platform and BiW development are the simulation driven concept development process (C123) and the Altair Multi-Disciplinary Optimization process (Altair MDO), see Figure 3.
Simulation Driven Concept Development, C123
C123 is a three-step process to actively support the early concept design of vehicle architectures, platforms, and vehicle bodies. The process sets off at very early concept as soon as concept packaging and styling are available.
C1 is concerned with the definition of efficient load paths considering constraints from crash, NVH, durability and misuse load cases. The goal is to shake down load paths concepts to consider one or multiple vehicle variants of a platform or architecture. C2 supports the early dimensioning of the load paths developed during C1.
The C2 model is a beam element dominated model. The beam properties however, are directly associated with the properties of real- life BiW cross sections. Thus, the C2 process will help find and dimension structural cross sections from a master section book of the OEM.
A similar strategy is used to dimension structural joints and connection areas of the vehicle structure. Finally, the C3 phase is concerned with improving the maturity of the structure established in C2 using a series of optimization based design loops combined with continuous verification.
The time allocated for the C123 process is controlled by the time allocated by the OEM for early concept development. The process is focused on design exploration and the OEM decides the time available for design exploration in different phases of concept development.
Figure 2: Overlay of a simulation driven design organization on vehicle development (red). This type of structure is often denoted “Optimization Center”
Altair | Feature
Figure 3: Altair Vehicle Level Simulation Driven Design Processes
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Altair Multi-Disciplinary Optimization, Altair MDO
Altair MDO are processes supported by an MDO tool to actively provide design decision input to the vehicle design process using multi- disciplinary optimization methodology.
The classical challenge of managing the complexity of a BiW MDO study is mitigated by a unique MDO tool and especially by its user interface.
The interface efficiently supports the loading and synchronization of multiple simulation models intended for different solvers and
used for different load cases. It supports the definition of design variables, responses, and constraints throughout the range of models and helps setting up one or more DOE studies to create the basis the solution of a response surface optimization problem.
To reach the goals to actively support the design process, methods and technology
have been introduced to reduce the number
of samples (simulations) for the DOE required to create the response surfaces for the MDO optimization to a certain quality.
Evaluation and design exploration capabilities are included to enable an active in-time support of the BiW design team. In a working environment, the complete MDO process is intended to be possible to execute within a two- week period, delivering first attribute feedback to design teams after two to three days
Benefit
The Altair vehicle level simulation driven design processes are developed to provide continuous in-time, relevant design decision input into the vehicle development process. Up-front design exploration based on FE and optimization will improve design maturity in all phases of vehicle development and will allow the design team to explore new and alternative design solutions without increasing development risks.
The processes will help find a better balance for fulfilment of weight, attribute performance and cost requirements. Finally, the simulation driven design processes will support the avoidance of late costly firefighting in vehicle development to reach weight, cost and/or attribute targets.