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white paper

Component-based transfer path analysis (TPA) for predicting NVH performance

Drivetrain noise is less prominent in hybrid and electric vehicles, making noises from other systems more noticeable. This is challenging automotive OEMs to find technologies that enable target assembly noise predictions from individual component models derived from simulation or test bench measurements to avoid costly and time-consuming design iterations. A relatively new solution, component-based TPA enables a quick assessment of many design variants and permanent proactive control of noise, vibration, and harshness (NVH) performance, allowing the early detection of potential NVH issues and system optimization in development.

Download the white paper to continue reading about the guidelines for predicting component NVH performance before building the first vehicle prototype.

What is component-based TPA?

Transfer path analysis (TPA) is a methodology for mathematically evaluating noise contributions from the source to the receiver. In contrast, component-based TPA is a virtual prototyping methodology to characterize noise source components independently from the receiver structure. Unlike traditional TPA, component-based TPA is a noise source identification methodology that pays particular attention to components rather than the assembled product. Automotive manufacturers can apply component-based TPA as noise source identification technology to predict vehicle system-level NVH performance based on individual component testing and set realistic component targets. Component-based TPA aims to identify the independent source loads from test rig data and combine them with a receiving structure to predict NVH performance in a virtually assembled configuration.

Accurately predict NVH performance before the first vehicle prototype is built

As a result of electrification, the automotive industry faces more complex products and an increasing number of vehicle models due to the variety of powertrain options. When developing complex products involving many assemblies, NVH issues are unfortunately often only discovered late in the design process. Different components interact once integrated into the full system, making it difficult to pinpoint which part is causing poor NVH performance. This concept of virtual prototyping using component-based TPA enables a quick assessment of many design variants and permanent proactive control of the NVH performance. It allows early detection of potential NVH issues and system optimization before building the first physical prototype, where the impact and cost of making modifications are still limited.

Demonstrating the component-based TPA process with an e-motor application case

Component-based TPA explicitly uses the concept of blocked forces to characterize active components independently of their integrated system application to allow active and passive components to assemble and analyze the noise contributions from active components in the whole system. This white paper uses an e-motor application case to illustrate the different steps of the component-based TPA process. In the first step, the e-motor is characterized independently according to ISO 20270: indirect measurement of blocked forces and ISO 9611: measurement of free velocities. Next, assembly predictions are made using substructuring techniques that can help accelerate engineering decisions. Finally, the target response is predicted to assess the performance of the engine component in the new assembly using blocked forces, free velocities, and ISO 21955.

Continue reading the white paper to learn more about component-based TPA solutions that help automotive manufacturers meet NVH design targets for all vehicle variants while controlling development time and cost.