Tensile yield in compact bone is determined by strain, post-yield behaviour by mineral content

Compact bone specimens from many species were examined to determine the relationships, in tension, between mineral content, Young's modulus, yield stress, yield strain, post-yield stress, post-yield strain, ultimate stress, ultimate strain and work under the stress-strain curve. Yield strain varied much less than the post-yield strain, and yield stress was strongly dependent on Young's modulus. Mineral content was a rather poor predictor of yield stress. However, post-yield events were predicted better by mineral (calcium) content than by Young's modulus. The greater the mineral content the less the post-yield work under the curve and the less the increase in post-yield stress and strain. The findings are compared with those of Les et al. who compressed specimens from equine metacarpals. Where they can be compared, the results are consistent with each other. (C) 2003 Elsevier Ltd. All rights reserved.