Measuring fracture toughness in biological materials

作者：Taylor David^*

来源：Journal of the Mechanical Behavior of Biomedical Materials, 2018, 77: 776-782.

DOI：10.1016/j.jmbbm.2017.07.007

• Fracture toughness
• Crack
• Eggshell
• Cuticle
• Soft tissues
• Cartilage
• Bone

Many biological materials fail by cracking. Examples are bone fractures, contact damage in eggs, splits in bamboo culm and defects in cartilage. The mechanical property that best describes failure by cracking is fracture toughness, which quantifies the ease with which cracks propagate and defines a material's tolerance for preexisting cracks and other stress concentrating features. The measurement of fracture toughness presents some challenges, especially for biological materials. To obtain valid results requires care and, in many cases, considerable ingenuity to design an appropriate specimen and test protocol. Common mistakes include incorrect interpretation of the mechanics of loading in unusual specimen designs, and failures occurring at the material's ultimate tensile strength as a result of specimens or cracks being too small. Interpretation of the resulting toughness data may also present challenges, for example when R-curve behaviour is present. In this article, examples of good and bad practice are described, and some recommendations made.

• 出版日期2018-1