USMA Athena

USMA Athena is a secure digital service managed by the United States Military Academy Library to make the work of USMA scholars freely available, while also ensuring these resources are organized to preserve the legacy of USMA scholarship. The mission of USMA Athena is to showcase the academic impact and intellectual capital that has become synonymous with the celebrated heritage of educational prowess attributed to the Long Gray Line. Scholarship submitted to USMA Athena benefits from added visibility and discoverability via Google Scholar in addition to the use of persistent URLs that will provide enduring access to the work over time.


Recent Submissions

Sharpening the Blunt Tool: Why Deterrence Needs an Update in the Next U.S. National Security Strategy
(The Strategy Bridge, 2021) Wolfley, Kyle J.
The 2017 U.S. National Security Strategy appeared to bring deterrence back: departing from its predecessor, the document prioritized the concept by including “preserving peace through strength” as a vital national interest. From nuclear weapons to cyberspace, the strategy emphasized the logics of denial and punishment, which were hallmarks of the classical deterrence theory that emerged after World War II. However, recent thinking on deterrence has evolved beyond these simple logics. Now emerging concepts such as tailored deterrence, cross-domain deterrence, and dissuasion offer new ideas to address criticisms of deterrence in theory and practice. Therefore, the most vital question for the new administration is: how should the U.S. revise its deterrence policy to best prevent aggression in today’s complex environment? A review of the problems and prospects in deterrence thinking reveals that in addition to skillfully tailoring threats and risks across domains, U.S. policymakers should dissuade aggression by offering opportunities for restraint to reduce the risk of escalation.
Summary of the Behavior of Steel-Plate Composite (SC) Walls Subjected to Implusive Loads
(Structural Mechanics in Reactor Technology (SMiRT-23), 2015) Bruhl, Jakob C.; Varma, Amit
Steel-plate composite (SC) walls are a viable alternative to reinforced concrete (RC) for protective structures and offer several advantages over RC. Current blast resistant design standards describe methods to design protective structures using RC, structural steel, or masonry in part because of the available experimental database for these materials to validate design methods. While there are blast test results of steel-concrete composite panels available in the literature, they are few and the majority are of specific configurations making it difficult to extrapolate to general behavior. This paper reports representative experimental results of simply supported one-way steel-plate composite (SC) wall sections, designed in accordance with AISC N690s1 Appendix N9 (AISC, 2014), and loaded with short duration uniform pressure pulses representative of far-field blast effects. Two numerical methods to assess the performance of SC walls subjected to blast loads are discussed and comparisons of experimental to numerical results are provided.
Steel-Plate Composite Walls Subjected to Missile Impact: Experimental Evaluation of Local Damage
(American Society of Civil Engineers (ASCE), 2021-02) Kim, Joo Min; Varma, Amit; Seo, Jungil; Bruhl, Jakob C.; Lee, Kyungkoo; Kim, Kapsun
This paper presents the results of an experimental program conducted to evaluate the local damage behavior of steel-plate composite (SC) walls subjected to missile impact. There is significant interest in the use of SC walls for protective structures particularly to resist impactive and impulsive loading. The behavior of SC walls subjected to these loads differs from that of reinforced concrete (RC) walls due to the placement of steel plates on the surfaces, which prevents concrete scabbing and enhances local perforation resistance. The results from the experimental program are used to demonstrate and explain progression of damage modes leading to local perforation, and to validate and quantify the conservatism of a recently developed design method. Laboratory-scale SC wall specimens were fabricated and tested in an indoor missile impact facility specially built and commissioned for this research....
Teaching Experimental Design in a Fluid Mechanics Course
(ASEE, 2018) Norberg, Seth; Ashcraft, Tim; Miller, Matthew Louis; Benson, Michael J.
In this paper we discuss the development and implementation of a new Design of Experiment (DoE) experience in the junior-level Thermal-Fluid Systems course. The goal of the DoE is to teach students about dynamic similarity, uncertainty quantification, and technical communications through a hands-on experience with direct connections to real-world applications. In the newly-designed DoE, students must determine whether they can accurately predict pressure drop in real-world pipe systems---including an oil pipeline, a ventilation duct, a natural gas line, and a water supply line---using the equipment we provide. Although the equipment is prescribed, the procedure is not, which has the benefit of minimizing material requirements while allowing students the freedom to pursue a unique approach. The experience is divided into stages with a mixture of individual and group efforts. Students begin by deriving the relevant equations and crafting an experimental procedure as an individual. They then come together in groups of three or four to conduct the experiment and analyze the data, which includes uncertainty quantification. An instructor provides feedback on the data analysis portion before students communicate their results in a short lab report with extensive appendices. Throughout the experience students are required to communicate the limitations of their experiment by quantifying uncertainty and questioning the validity of their assumptions. Overall, the DoE is an exercise in critical thinking, data gathering, analysis, and interpretation of results. We present details of the DoE assignment, assessment of student learning, student feedback from course evaluations, and recommendations for instructors seeking to implement similar projects in their courses.
Stimulating Higher Order Thinking in Mechatronics by Comparing PID and Fuzzy Control
(Computers in Education Journal, 2019) Lowrance, Christopher J.; Rogers, John R.
Many studies have found active learning, either in the form of in-class exercises or projects, to be superior to traditional lectures. However, these forms of hands-on learning do not always get students to reach the higher order thinking skills associated with the highest levels of Bloom’s Taxonomy (i.e., analysis, synthesis, and evaluation). Assignments that expect students to take an expected approach to reach a well-defined solution contribute to a lack of higher order thinking at the college level. Professional engineers often face complex and ambiguous problems that require design decisions, where there is no straightforward answer. To strengthen the higher order thinking skills that these problems demand, we developed a project in our semester-long mechatronics course where students must evaluate two automatic control methodologies for an application without being given explicit performance criteria or experimental procedures. More specifically, the project involves determining the superior control method for leader-follower behavior in which a ground vehicle autonomously follows behind a lead vehicle. Laboratory exercises throughout the semester expose the students to the skills they need for the project: using sensors and actuators, programming a proportional-integral-derivative (PID) controller and a fuzzy controller, and using computer vision to detect the signature of an object. In the final course project, they go beyond implementing individual controllers and create their own evaluation criteria and experiments for making a design decision between PID and fuzzy control. We implemented this approach for three semesters, and our significant findings are: 1) students generally appreciate the aspect of working on a real-world and open-ended problem, 2) most teams developed creative performance criteria and methods for evaluating controller performance, clearly demonstrating higher order thinking, and 3) students discover that creating a comparative study is nontrivial due to the number of factors that influence performance, which mimics the practical problems they will likely face as engineers.