Brown University School of Engineering

Choe '15 uses UTRA to Conduct Engineering Analysis of Bow and Arrow

July 26, 2013
Ahyoung Choe ’15

Choe, mechanical engineering concentrator, is conducting experiments and research on the bow and arrow. Here, she is preparing to capture high speed photography images and video of the bow and arrow.

Credit: Amy Simmons/Brown University

Ahyoung Choe ’15, a mechanical engineering concentrator, is spending her summer in Providence conducting research through an Undergraduate Teaching and Research Award (UTRA). With the help of faculty mentors Professor Allan Bower and Professor K.S. Kim, Choe is conducting experiments and research on the bow and arrow.

From Engineering Mechanics to the Hunger Games: the Engineering, History and Mythology of the Bow and Arrow

The bow and arrow is as old as the wheel, and its influence on humankind has been no less profound.  It provided early man with a source of food and clothing; for centuries, it was the predominant weapon of war, and has helped develop, sustain, and destroy empires.  The significance of the bow and arrow is enshrined in the myths and legends told by the peoples who relied on them for their sustenance and protection, and the tales of Go Jumong, William Tell, Robin Hood, and Katniss Everdeen continue to entertain and inspire us today.

Although all designs exploit the same basic principles, every culture developed its own unique version of the bow and arrow. These design differences influenced the way the bow was used. However, even though the principles underlying the operation of a bow and arrow are well understood, surprisingly little is known about how a bow’s design affects its performance. With this in mind, this research project seeks to answer the following questions:  

1)      How does the design of a bow and arrow affect its performance?

2)      How are the characteristics of these designs reflected in the way they were used throughout history?

3)      Do popular myths and legends surrounding the bow and arrow have any basis in fact?

http://www.youtube.com/watch?v=FH7RUU0IFeE&feature=share&list=UU3Xb71wn86DUXPfGe-NDYjA

Engineering analysis of the bow and arrow

A combination of computer simulation and high-speed photography will be used to study the performance of three representative designs for the bow and arrow: (i) the English longbow; (ii) the Mongolian recurve bow; and (iii) a modern compound bow.  A computer model of each bow will be constructed, and a commercial finite element code (ABAQUS) will be used to predict how the bow deforms while it is loaded and fired. The computations will predict 1) how much energy can be stored in each bow without fracture, 2) the amount of energy that can be transferred to the arrow once fired, and 3) the velocity of the arrow just after it leaves the bow. To check the calculations, each bow will be fired under safe, controlled conditions in the laboratory, and high-speed video will be taken of the bows’ motion during firing.

The bow and arrow in history

This portion of the study will examine how the three bows were used in practice, making use of primary and secondary sources. In particular, the study seeks to find correlations between the performances recorded in the engineering analysis with their tactical use. To narrow the focus of research, the Hundred Years’ War, in which the longbow has been credited with contributing to the victories for the English, and the Mongol invasions under the rule of Chinggis Khan will be studied.

The bow and arrow in mythology and popular entertainment

This portion of the study will compare and contrast myths and legends centered on the bow and arrow from various cultures. The study will attempt to determine whether the differences in performance attributed to legendary and mythical archers correlate with the characteristics of the bows.

The results of her research will presented on Friday, August 2 at the annual Summer Research Symposium at Sayles Hall.