Vibracoustic

From Initial Design to Serial Production and Beyond

We follow a holistic approach by closely collaborating with the engineering departments of our customers at each stage of the development process. We rely on our deep expertise, our many years of experience and our pioneering test bench in Europe, the Americas and Asia. 

Our testing equipment consists of a four-post shaker, a roller test bench in an anechoic chamber, axle test benches and measurement technology. Our capabilities to analyze high frequency concepts are exceptional on the NVH market.

Holistic Testing Experience

These assets enable us to conduct acoustic analyses as well as comprehensive experimental and virtual vibration performance analyses at the vehicle, sub system or component level. The goal is to solve the conflict of objectives to optimize NVH performance without compromising the vehicle’s handling performance. On the four-post shaker and acoustic roller test bench, we analyze, optimize and benchmark the impact of the vehicle architecture and its components on NVH performance. To this end, we consider parameters such as seat rail and sub frame vibrations, displacements or operational deflection shapes. With our four-post shaker, we can excite every single wheel or a combination of wheels vertically to investigate vehicle behavior and correlate the vehicle performance with our simulation models.

NVH-Expertise-Testing

Tests on our acoustic roller test bench help us to identify emissions originating from electric and conventional motors and drive shafts as well as interior noise sources.

We use measurement technology for test data acquisition and processing: our equipment can record more than 150 data channels simultaneously and process them in connection with data derived from the vehicle’s internal CAN bus system. The signals come from e.g. accelerometers throughout the vehicle, microphones inside the vehicle and near the motor, or temperature sensors close to the motor mounts.

On the axle test bench, we analyze, optimize and benchmark component functions within the axle subsystem and identify multiple system stiffnesses. We analyze free vibration of the axle and the impacts of e.g. run-ups and unbalanced wheels to understand the longitudinal and vertical forces and their influence.

We know how each component interacts with the axle or the entire vehicle and identify component parameters like non-linear static forces, dynamic hardening as well as dynamic stiffness and damping factors. With the results from the experimental analyses we optimize the design for the components. The outcome is the identification of all root causes and sensitivities, which allows us to define and refine the component specifications.


Translating Specifications into Perfect NVH Solutions

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Once component specifications and requirements, like installation space, life span, mounting points, static and dynamic loads, driving characteristics and the DNA of each specific vehicle are defined, we develop the part design via Computer Aided Engineering.

Finite Element Analysis enables us to reduce the number of physical prototypes and experimental analyses since we can optimize components already in their design phase. We rely on more than 60 years of automotive NVH experience and our specific prediction tools and global templates for CAD and drawings.

Essential for the overall physical and chemical behavior of the component structure is our deep material science expertise. We know how to find the perfect mix of natural and synthetic polymers to address the specific NVH challenges of our customers in terms of durability and dynamic hardening. Whether it is elastomers, dual-component materials, temperature-resistant Ethylene Propylene Diene Monomer (EPDM) or Micro Cellular Urethane (MCU), we offer reliable materials to reduce noise, vibration and harshness.

Our compound families are developed well in advance in line with future NVH market trends, are process-safe and suitable for serial production. The materials of our compound families are tested in the laboratory for their rheological characteristics as well as for their reaction kinetics and scaled-up for industrialization. We are the go-to partner when it comes to providing the right material mix and the know-how for related processes, e.g. vulcanization and adhesion characteristics, rubber and silicone injection behavior or innovative welding processes.


On the Way to Serial Production

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We use Computer Aided Engineering (CAE) tools to analyze and validate our components profoundly through their phases at the component, sub system and vehicle level. We precisely predict the performance of each component over its lifespan, on all platforms and all drive concepts. For example, we use Finite Element Methods for predicting the behavior of the components’ properties, tools for designing hydraulic components and durability prediction as well as proprietary software modules in ADAMS to simulate and design multi-body systems.

Once we have defined the part design via CAE and have chosen the right material mixing family, we manufacture prototypes of our components for validation before serial production.

The experimental and virtual validation and testing of prototypes make sure that our solutions meet the NVH performance criteria of our customers and allow us to adjust the geometries of the component if necessary.

We use our standardized processes and state of the art testing facilities to thoroughly verify the characteristics of the components in experimental analysis. For example, we conduct multi-axial testing to check on static and dynamic characteristics for all relevant directions. We conduct several internal tests for our prototypes like static tests, dynamic analysis on high-frequency test machines, a broad range of shore hardness tests for rubber components or stress tests and endurance tests with influences of chemical stress factors, like oil and ozone. Addressing real-world requirements in our testing ensures correct remeasurements and the precise updating of parameters. Our testing and simulation efforts always result in the optimal design and performance of the NVH component.

Last Minute Changes on the Spot

Linear Damper Toolbox Provides NVH Improvement within Minutes

We support our customers late in the design process of the vehicle with a comprehensive portfolio of linear dampers, a quick and easy solution to address unwanted noise. The dampers can be added to the respective area or component of the vehicle which causes the issue. We provide a toolbox of customized damper prototypes, which can be swapped out within minutes during the actual testing at the customer’s testing facilities and provide instant NVH improvement.

Finetuning the Characteristics of Air Springs within Hours

We support our customers to adjust the stiffness of air springs regarding the perception of the test driver during final vehicle testing on the customer’s test tracks. Our engineers discuss the tuning options with the test driver and translate this into different stiffness characteristics. In our mobile tuning container, we optimize these characteristics via simulation tools, calculate the shape of the rolling piston of the air spring and produce the new shape on an onboard CNC machine. Within hours, the adapted air spring is ready for a new vehicle test.