Concepts of a Battery Box Vibration Absorber for a Durable, Lightweight Structure

Overview

The sponsor, Volvo Group North America, has tasked the project team with the overall goal of designing a durable, lightweight vibration absorber to be placed on the battery box to reduce vibration-fatigue on the chassis using advanced software and simulations. This will extend the overall fatigue life of the chassis and allow a lighter weight chassis design to be implemented down the line.

Objectives

Team objectives are to review vibration of 2 DOF systems, create ideas for vibration absorbers with the DMAIC (Define, Measure, Analyze, Improve, Control) method, become familiar with finite element analysis software through training, develop concepts to reduce battery box vibration, and validate/present concepts to sponsor.

Approach

This project focused primarily on the vibration absorber concept generation process using the DMAIC (Define, Measure, Analyze,
Improve, Control) Method. This method consisted of the following steps:

Define: Develop an understanding of the problem and customer needs to brainstorm concepts for a vibration absorber. Perform a literature review to investigate existing products and ensure design does not conflict with existing patents.

Measure: Create CAD Models for and run finite element analysis simulations with provided software (Hyperworks Optistruct) to obtain vibration fatigue data for each concept.

Analyze: Evaluate the simulation results by creating an acceleration vs frequency plot to compare vibration amplitude of concept to the baseline. Calculate percent amplitude reduction and fatigue life to evaluate effectiveness of concept.

Improve: Continue developing and improving concepts to better meet the customer needs and more effectively reduce vibration amplitude.

Control: Validate findings by presenting results to sponsor and performing more in depth simulations of the electric truck chassis model.

Outcomes

Frequency analysis resulted in the absorber design reducing the vibration amplitude by greater than 50% compared to the original design.

Fatigue analysis resulted in the absorber design increasing the overall vehicle fatigue life by 1.4 times more than the original design.

Using this concept, the chassis can be designed to be lighter weight, saving cost and increasing efficiency for future electric truck chassis.

Absorber design can be adjusted to be added to other parts of the vehicle and other Volvo battery packs.