While some of think of our cars as simply "buckets of bolts", the proper design choices, applications, and assemblies of threaded fasteners/bolted joints play critical roles in automobile safety.

Supplemental Restraint Systems (SRS), more commonly known as airbags, help prevent vehicle occupants from being thrown forward into the dashboard or windshield in the event of a collision. The components comprising the airbag, the inflator, the backing plate, and the cover are connected to each other, and to the vehicle, through a series of threaded fasteners. Proper and timely deployment of the airbag depends largely on the selection of suitable threaded fasteners at the design stage, appropriate fastener application, and strict adherence to the module assembly process.

Selecting suitable fasteners and applying fasteners appropriately requires an understanding of basic fastener concepts: thread definitions, fastener loading terms, stress and strength, and joint failure modes. Knowledge of torque, preload, torque equations, and torque control also is necessary before proper selection and application can occur.

The Case Study examines a drivers' side airbag module currently used on a vehicle marketed in the United States and, employing applicable design equations, determines 1.) if the design selection of the threaded fasteners is appropriate, 2.) how the threaded fasteners behave during and after airbag assembly, and during airbag deployment, and 3.) the potential problems arising from loose or missing fasteners.

The thesis concludes the design and selection of the fasteners used in the airbag module concurs with the basic principles of threaded joints. Through the cases selected for the modules, the thesis generates several conditions that must be met to prevent joint failures.

It is proposed that this research be used to further determine both the design selection of threaded fasteners and the assembly processes of automotive airbag manufacturing.


If this is your thesis or dissertation, and want to learn how to access it or for more information about readership statistics, contact us at STARS@ucf.edu

Graduation Date





Hagedoorn, A. Henry


Master of Science (M.S.)


College of Engineering


Mechanical, Materials, and Aerospace Engineering






Written permission granted by copyright holder to the University of Central Florida Libraries to digitize and distribute for nonprofit, educational purposes.

Length of Campus-only Access


Access Status

Masters Thesis (Open Access)



Accessibility Status

Searchable text

Included in

Engineering Commons