Date of Award

Summer 2015

Document Type

Thesis

Degree Name

Master of Science in Mechanical Engineering - (M.S.)

Department

Mechanical and Industrial Engineering

First Advisor

N. Chandra

Second Advisor

Siva P.V. Nadimpalli

Third Advisor

Zhiming Ji

Abstract

Blast related brain injuries are commonly encountered in the recent wars of Iraq and Afghanistan increased use of improvised explosive devices (IEDs). An estimated 20% of veterans returning from these operations have suffered traumatic brain injuries (TBI). The mechanisms and long-term effects of the injury are not fully understood, and extensive research effort is being focused toward identifying the mechanisms of primary blast injury. When a pure shock-blast wave encounters a subject, in the absence of shrapnel, casing or gaseous products, the loading is termed as primary blast loading, and its effects can be studied using shock tubes.

The wave profile of the shock-blast wave produced by the shock tube is characterized by blast overpressure, positive time duration, and impulse. Evolution of the blast wave profiles along the length of the compression driven gas shock tube is studied using experiments and numerical simulations. It is important to identify Shock-blast wave parameters (SWPs), and understand the relationships between the shock tube adjustable parameters (SAPs) and SWPs, in order to control blast wave profiles.

In this thesis work, the position of the end plate is the SAP that is specifically studied. Since the shock tube has an open-ended configuration, in order to contain the shock-blast wave and obtain an acceptable Friedlander curve, an endplate was attached to the open end, as a design concept. It was found that the endplate to shock tube end distance affected the shock wave profile. In this research work, the endplate distances were varied and the evolution of shock profile was measured. It was found that at 4 inches distance from the open end, in the current configuration of the shock tube, the desired Friedlander curve was achieved. At other distances, secondary reflection effects were noticed.

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