No abstract

No abstract

A locking compression plate (LCP) can serve as an external fixation for fractured tibia. However, there is concern about the stability and endurance during partial weight bearing. This study was experimentally evaluated the effects of fracture gap sizes (1, 5, and 10 mm) on the stability and endurance of fractured tibia externally fixed with a 316L-stainless LCP. For stable fractured tibia (1-mm fracture gap), the large contact area of fracture surfaces resulted in nearly similar stiffness to that of intact tibia. The partial weight bearing is therefore possible. Whereas smaller contact area and no contact of fracture surfaces were observed for tibias with 5-mm and 10-mm fracture gaps, respectively. Their stiffnesses were significantly lower than those of intact tibia and tibia with 1-mm fracture gap. Thus, the partial weight bearing should be considered carefully in early phase of treatment. All LCP-tibial models were cyclically loaded beyond 500,000 cycles, that is, approximately 6 months of healing, without any failure of LCP. Thus, the failure of LCP is unlikely a critical issue for the present cases.

Low-cycle fatigue (LCF) data of Sn-Ag eutectic solder (96.5Sn-3.5Ag) under various temperatures and frequencies has been described using three different prediction models, i.e., Coffin-Manson model, Smith-Watson-Topper (SWT) model, and Morrow energy model. The LCF behavior represented by the present prediction models showed temperature and frequency dependences, i.e., the fatigue ductility coefficient increased with increasing frequency and decreasing temperature. In order to better correlate the LCF data, a flow stress and/or frequency-dependent modifications were introduced to the Coffin-Manson and Morrow energy models. The frequency-modified Coffin-Manson model could not describe the influence of temperature on LCF behavior, while the flow stress-modified frequency-modified Morrow energy model, into which the metallurgical response (flow stress and frequency) was introduced to account for the effect of temperature and frequency on LCF behavior, gave reasonable predictions of LCF data under various temperatures and frequencies.

No abstract