SURVICE Monographs are one-volume compilations of technical information/research intended to document unique information, insights, experiences, and/or methodologies from subject-matter experts for the purpose of staff development, community enhancement, and/or information archiving. For more information contact Eric Edwards or visit dsiac.org.
SURVICE Monograph 15-001, “Ballistic Equations: A Compilation of Equations and Methods for Evaluation of Parameters Relevant to Penetration, Blast Effects, and Crater Formation,” James N. Walbert, August 2015
Critical to combat system survivability analysis is the ability to estimate the effects of threat-target interactions. However, this ability is particularly challenging given the inherent variability in the fundamental physical processes of detonation physics, fracture mechanics, and penetration mechanics. Thus, the analyst must seek to bound the problem and its solution set (e.g., using first-order estimates) and find a range of possible outcomes given a range of initial conditions. This document is a compilation of equations and methods that form the basis for a number of analytical tools designed to provide first-order estimates of the effects of ballistic-related penetration and blast. Penetration equations include those for small-caliber projectiles, fragments, or shaped charge jets; blast equations include estimation of blast parameters, crater formation, and the deformation and/or fracture of flat or curved plates impacted by blast. Some of these equations are based on first-principle physics; most are empirical in nature. In addition, appendices to the document include relevant THOR data sets, THOR and Joint Technical Coordinating Group for Munitions Effectiveness (JTCG/ME) penetration constants, and drag coefficients for small-caliber projectiles.
SURVICE Monograph 14-001, “Time Series Analysis and Its Application to Ballistic Data,” James N. Walbert, August 2014
This monograph is intended to serve as an introduction to the topic of time series analysis, documenting numerous methods for analysis of ballistic data, such as pressure and acceleration. The methods have applicability beyond ballistic data as well.
SURVICE Monograph 14-002, “An Introduction to Ground Combat System Ballistic Vulnerability/Lethality Analysis,” James N. Walbert, August 2014
The monograph is based on a training course developed and taught by the author to ground combat system vulnerability/lethality (V/L) analysts for the Department of Defense. The text focuses on the fundamental methodologies, approaches, models, tools, and practices that are (or should be) used in conducting V/L studies. Extensive coverage is also given to mathematical counterexamples and statistical anomalies, as well as common misuses and misinterpretation of data, mathematical and statistical methods, and the natural variability inherent in physical processes.
SURVICE Monograph 13-001, “An Overview of Blast and Its Effect on Combat Systems,” James N. Walbert, May 2013
The use of large explosive charges—whether in the form of military mines or improvised explosive devices (IEDs)—detonated under ground combat systems has long been a source of concern for those responsible for developing, analyzing, and improving these systems. And this concern has only increased in recent years as the use and size of these charges have markedly increased in modern combat zones. Unfortunately, while attempts to mitigate the effects of these charges on combat systems and their occupants have been widely reported in the media and elsewhere, the reports have often misrepresented the true physics and mechanics of the mitigation mechanisms. Thus, this monograph is intended to provide survivability analysts, designers, testers, and field assessors with a more complete understanding of the subject by defining pertinent terminology, describing the fundamental physics of blast and other detonation products, examining various aspects of mitigation, and dispelling certain myths that surround these phenomena.
SURVICE Monograph 13-002, “Projectile Aerodynamic Approximations Derived in Closed Form From Limited Data,” Fred Malinoski and James Walbert, September 2013
These approximations provide simple, easy-to-calculate one-dimensional values for various aerodynamic functions for projectiles, such as range as a function of velocity, time as a function either of range or velocity, and drag as a function of velocity, assuming there are data on any one of them. In the absence of actual data or full three-dimensional computational methods, these approximations enable trajectory calculations not otherwise possible.