Influence of Momentum and Energy on Materials: An Experimental and Molecular Dynamics Approach for Impact Phenomena

• Published in: Steel research international Vol. 88; no. 10; pp. 1600445 - n/a
• Main Authors: Winkelmann, Horst, Rojacz, Harald, Eder, Stefan J., Varga, Markus, Nugent, Severin
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 01.10.2017
• Subjects: Carbon steel; Computer simulation; Deformation; Energy consumption; Heat treatment; impact; Impact tests; material modeling; Mathematical analysis; Molecular dynamics; molecular dynamics simulation; Parameter sensitivity; steel
• ISSN: 1611-3683; 1869-344X
• DOI: 10.1002/srin.201600445

Single‐impact tests and molecular dynamics (MD) simulations are performed to evaluate effects at energy‐ and momentum‐variable impact phenomena at two distinct scales and velocity ranges. Therefore, a carbon steel in various heat treatment conditions is examined using the single impact test to evaluate the influence of varying energies and momenta on the deformation behavior. Experimentally found material parameters “momentum‐sensitivity”ps(E) and “minimum deformation momentum”p0(E)are introduced for a better mathematical description of impact phenomena or deformation processes using energy and momentum. Empirical laws are found, where the minimum deformation momentum is a linear function of the impact energy (E) and the deformation at low momenta is an inverse function of E, which has significant influence on the deformation. The proposed empirical law are recalculated via down‐scaled molecular dynamics simulation (rigid indenter impacting on an iron block) and is found applicable for macro and nano scale impact phenomena. Impact studies are performed on macro and nanoscopic levels. Energy dependent parameters momentum sensitivity ps(E) and minimal deformation momentum p0(E) are found. Momentum sensitivity expresses how fast the deformation saturates at certain energies and momenta. The minimal deformation momentum represents the threshold for plastic deformation. Found empirical material laws for deformation behavior fit on both examined levels.