Relative tensile strengths of chainmail weaves

Abstract

Chainmail is a type of body armor that has been used throughout ancient and modern times by a variety of people, including medieval fighters and ocean divers. Articles of chainmail are made out of interconnected metal rings - usually steel rings - that are either butted, welded, or riveted together. The primary failure mechanism of a piece is usually the rings being pried apart by a wedge-shaped object, such as the tip of a sword or a shark tooth. The ability of an article of chainmail to resist such failures depends on a variety of variables including the method of closure of the rings, the diameter and gauge of the rings used, and the weave type. The relative strengths of different types of chainmail were investigated by conducting tensile tests on both physical and simulated samples. Eight different ring diameters, four different ring gauges, four different weaves, and three methods of closure of the rings (butting, riveting, and welding) were tested. For both methods of analysis, force-displacement curves were generated for each sample, and the yield forces, maximum forces, and effective elastic moduli extracted from the graphs. Proportional relationships between the physical characteristics of the chainmail and the forces and moduli were obtained graphically through analysis of the experimental data. The yield and maximum forces were determined to vary directly with the number of rings linked to a given ring, with an average error of 10.66 5.67 %. These parameters were also found to vary inversely with the ring diameters, with an average percent error of 14.63 5.61 %. The samples with welded rings were found to yield at a force at least 1.5 times higher than the yield force of the riveted samples and at a force at least 2 times higher than the yield force of the butted samples. The effective elastic moduli decreased with increasing diameter and held relatively constant across the different methods of ring closure. The attempt to scale the forces and moduli with the cross-sectional area of the rings proved inconclusive due to large percent differences between the scaled values. The experimental results were compared to those generated by nonlinear, dynamic SolidWorks simulations. The verification of the simulated results with the experimental results allowed investigation into possible sources of error in the experimentation via simulation. Variations in the orientation of the rings resulted in variations in the yield force up to 33.31%. The yield force was also found to decline as a rate of 100 N for each millimeter of width of the split in the butted rings. Thus, the simulations provided possible explanations for some of the larger percent differences found during the creation of the proportional relationships - including the inconclusive results for scaling with cross-sectional area. Despite the possibilities for error, there exists strong support for the scaling relationships established for weave type and ring diameter due to the low percent errors calculated, as well as the low percent errors between the simulated and experimental values.