© 2016 Siemens Product Lifecycle Management Software Inc. Siemens and the Siemens logo are registered trademarks of Siemens AG. LMS, LMS Imagine.Lab, LMS Imagine.Lab Amesim, LMS Virtual.Lab, LMS Samtech, LMS Samtech Caesam, LMS Samtech Samcef, LMS Test.Lab, LMS Soundbrush, LMS Smart, and LMS SCADAS are trademarks or registered trademarks of Siemens Industry Software NV or any of its affiliates. All other trademarks, registered trademarks or service marks belong to their respective holders.
44352-A7 8/16 P Vehicle handling analysis
By including flexible body modes in multi-body simulations, LMS
Engineering experts can visualize the body deformation during maneuvering and relate the body behavior to handling parameters (such as yaw rate or roll angle). These calculations reveal which forces excite the body for each time step, which body modes contribute and the relative importance of local versus global body stiffness for the connection point deformation, enabling studies on the impact of body modifica-tions. This combined information allows a weak-point analysis to evaluate and set body targets for improved vehicle handling performance.
Body concept modifications LMS Engineering experts investigate modifications that improve the overall performance. Beam concept modeling and advanced model reduction technol-ogy can help you study many modifica-tions and their effect on global vehicle behavior in short order.
Siemens PLM Software www.siemens.com/plm Americas +1 314 264 8499 Europe +44 (0) 1276 413200 Asia-Pacific +852 2230 3308
Vehicle handling analysis.
Body concept modifications.
Solutions for body
Summary
LMS™ Engineering services employ an integrated simulation approach to optimally balance noise, vibration and harshness (NVH) with vehicle ride and handling during body design.
Automotive engineers must consider several handling aspects while designing a vehicle, such as stability, agility and control. At the same time, a good body design results in enjoyable ride comfort and low road-noise levels.
Finding the right balance between these often-conflicting functional performance characteristics can be a real engineering challenge in which body stiffness plays a crucial role.
Multi-attribute balancing includes optimization of NVH and vehicle handling performance in an integrated simulation approach. By employing innovative body stiffness simulation methodologies, the body design can be optimized for both attributes at the same time in a comprehensive process.
Multi-attribute balancing for road noise and vehicle handling starts by creating a finite element model (FEM) of the body. This will be transformed into an equivalent body concept model, which can be employed to handle both characteristics simultaneously. This is in contrast to the customary approach, which addresses these characteristics in separate engineering processes, leading to contradictory solutions.
Including the body concept model in a full vehicle road-noise model with tire, wheel and suspensions and a full vehicle multibody handling model facilitates fast simulation loops for both attributes. By coupling parameters in both models and executing a large number of simulations, the optimal design can be found.
LMS Engineering services simultaneously optimize multiple attributes to identify optimal body design
Benefits
• Save resources and time by integrat-ing customary and contradictory approaches in
a unified engineering method
• Understand how body stiffness influ-ences NVH and vehicle handling char-acteristics by applying modifications in an optimization loop
• Find a solution that optimizes NVH and vehicle handling using computer-aided engineering
• Provide a common evaluation method to identify necessary compromises across attribute teams
Body balancing for NVH and vehicle
handling
Solutions for body
A typical multi-attribute balancing project for NVH and vehicle handling is comprised of the following phases:
Creating the body model
First, LMS Engineering experts create a detailed FEM model and use it as the basis to build a reduced fast-running model that produces exactly the same global structural modes. This body concept model is created by dividing the structure into functional
components such as beams and joints, and combining them with a modal system representation. Structural members with length significantly greater than the cross-section area (such as pillars and cross members) are modeled with beam elements, the joints between them with static superelements and the rest of the structure by a modal model.
Body balancing for NVH and vehicle handling
© 2016 Siemens Product Lifecycle Management Software Inc. Siemens and the Siemens logo are registered trademarks of Siemens AG. LMS, LMS Imagine.Lab, LMS Imagine.Lab Amesim, LMS Virtual.Lab, LMS Samtech, LMS Samtech Caesam, LMS Samtech Samcef, LMS Test.Lab, LMS Soundbrush, LMS Smart, and LMS SCADAS are trademarks or registered trademarks of Siemens Industry Software NV or any of its affiliates. All other trademarks, registered trademarks or service marks belong to their respective holders.
44366-A11 7/16 P Parallel road noise and vehicle
handling analysis
The body concept model is included in a full vehicle multibody model for handling, and a full-vehicle model for road noise that has suspension and trim. While LMS Engineering experts fine-tune the handling model, the road-noise model automatically adapts.
The efficiency of this solution allows for the evaluation of over a 1,000 variants in a single loop for optimizing both attributes at the same time.
Multi-attribute optimization
Finally, the optimized body stiffness is used as input for body design modification. This yields a new body model, which can be used to conduct repeated analyses until the desired performance is achieved. Further optimization can still include mounts and bushings as well.
Siemens PLM Software www.siemens.com/plm Americas +1 314 264 8499 Europe +44 (0) 1276 413200 Asia-Pacific +852 2230 3308 Full finite element model.
Body concept model.
Solutions for body
Summary
LMS™ Engineering services help you implement a methodology to create fast-running vehicle concept models that enable efficient evaluation of modifications to beam-like sections or joints so you can tune the global vehicle dynamics.
Today’s customers expect a broad range of high-quality vehicle variants at a reasonable price, calling for reduced development time and cost. Making
decisions based on virtual prototypes helps you meet this demand. When implementing an analysis-leads-design process, upfront engineering precedes detailed geometric design. This approach allows you to solve many problems in the early development stage, resulting in an initially higher-quality computer-aided design (CAD) model. Fast body optimization helps you investigate more alternatives within a given timeframe and increases analy-sis feedback to design engineers.
Fast body optimization employs physi-cal and modal substructuring of components to drastically reduce the calculation time for a full-scale finite element model, allowing more than 100 simulation runs in one day.
Combined with powerful contribution analysis and optimization tools, this approach enables you to reach global vehicle targets, such as the frequencies of the global modes, with an efficient and robust modification strategy.