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Compressive high cycle at low strain fatigue behavior of bovine trabecular bone
| Content Provider | Semantic Scholar |
|---|---|
| Author | Cheng, Deborah |
| Copyright Year | 1995 |
| Abstract | Micro fatigue damage to bone resulting from repetitive, low-intensity loading of normal activity is believed to play a significant role in stress fractures, bone remodelling, and spontaneous fractures in the elderly, with estimated medical costs of over $1 billion annually. Age-related fractures most frequently occur in trabecular bone sites, such as the vertebral body, the proximal femur, and the distal radius. Thus the compressive fatigue behavior of trabecular bone is important in the understanding of clinical orthopaedic issues. Fatigue experiments of trabecular bone can result in large data scatter if unintentional off-axis testing occurs. A technique that selects for well-aligned and homogeneous specimens to reduce data scatter has been developed (Keaveny et al., 1994). To validate the specimen selection technique, three-dimensional micromagnetic resonance images of specimens selected using the technique were obtained and analyzed. Results suggest that the use of contact radiography in selecting specimens ensures that the alignment and density of specimens are of an acceptable level. The validated technique was then used to select bovine trabecular bone specimens for compressive fatigue tests. Specimens were fatigued under loads corresponding to low stress levels using a test protocol that minimizes experimental artifacts (Keaveny et al., 1994) to accurately characterize the compressive fatigue behavior of trabecular bone. A single linear function relates the log normalized applied stress to the log number-of-cycles-to-failure along the entire normalized stress range tested. The slope of this function lies between those expected from modes of creep and slow crack growth (Guo et al., 1994). The fatigue experiments did not reveal distinct low and high cycle regimes, suggesting that fatigue damage may be caused by some combination of the creep and slow crack growth mechanisms or by additional, as yet unmodelled, mechanisms, such as creep buckling. Thesis Supervisor: Lorna J. Gibson Title: Associate Professor, Department of Civil and Environmental Engineering |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://dspace.mit.edu/bitstream/handle/1721.1/38042/32824716-MIT.pdf;jsessionid=44185708CC23E4977F4F7C62CC155C3F?sequence=2 |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
