Skip to Main Content
Table 2.

`Engineering' versus `true' stress and strain

Species (N)Maximum `engineering' stress (MPa)Maximum `true' stress (MPa)Δ`Engineering' strain at failure`True' strain at failureΔ
Geukensia demissa (19) 75.1±10.4 140.8±18.7 +88% 0.897±0.034 0.637±0.018 –29% 
Modiolus modiolus (20) 161.3±19.8 287.8±35.6 +78% 0.781±0.045 0.571±0.024 –27% 
Mytilus californianus (21) 111.0±11.7 215.3±25.3 +94% 0.901±0.032 0.639±0.016 –29% 
Mytilus edulis (25) 109.2±8.6 216.9±18.8 +99% 0.958±0.034 0.669±0.017 –30% 
Species (N)Maximum `engineering' stress (MPa)Maximum `true' stress (MPa)Δ`Engineering' strain at failure`True' strain at failureΔ
Geukensia demissa (19) 75.1±10.4 140.8±18.7 +88% 0.897±0.034 0.637±0.018 –29% 
Modiolus modiolus (20) 161.3±19.8 287.8±35.6 +78% 0.781±0.045 0.571±0.024 –27% 
Mytilus californianus (21) 111.0±11.7 215.3±25.3 +94% 0.901±0.032 0.639±0.016 –29% 
Mytilus edulis (25) 109.2±8.6 216.9±18.8 +99% 0.958±0.034 0.669±0.017 –30% 

Values given are means ± s.e.m. For both stress and strain and for all species, `true' values were significantly different from `engineering'values, allowing us to reject the hypothesis that changes in thread area and length during the testing procedure were insignificant (paired t-test: P<0.0001; paired sign test: P<0.0001). Note that the discrepancy (Δ) between`engineering' and `true' values increases as strain at failure increases

Close Modal

or Create an Account

Close Modal
Close Modal