Honors Theses


Margaret Pinnell


Mechanical Engineering

Publication Date

Spring 4-2015

Document Type

Honors Thesis


Two categories were used to assess the strength of duct tape constructions: adhesive strength and tensile strength. Previously made duct tape backpacks frequently suffered from adhesive failure around shoulder straps. When a backpack is lifted, it experiences a force which is greater than the resting weight. The hypothesis states that there is an area of application between two pieces of duct tape such that they will behave as a uniform piece and experience tensile failure, that two sufficiently overlapped pieces can hold within 5% of the load carried by a single piece, and that there is a relationship between the resting weight of a loaded backpack and the load applied to the straps when lifted.

Five types of tape underwent tensile and lap shear testing in an Instron 4486 load frame. The tension test specimens were of uniform length, the lap-shear specimens had lengths which varied with the areas of overlap. There were two types of lap shear specimens: with adhesive layers in contact (LSA), and with the adhesive of one half adhered to the backing of the other (LSN). Maximum load and extension data was collected. Three backpacks were tested to determine the apparent load carried by the shoulder straps and handles when various static loads were applied. The backpacks were lifted with a Desik analog push-pull gauge which recorded maximum load.

Permission Statement

This item is protected by copyright law (Title 17, U.S. Code) and may only be used for noncommercial, educational, and scholarly purposes.


Undergraduate research


Engineering | Mechanical Engineering