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Ligaments and tendons are fibrous connective tissues that connect the structures of the musculoskeletal system, enabling joint stability and force transmission, and finally motion. They consist of packed and oriented collagen fibers embedded in a water-based ground substance and show a high degree of architectural organization. Ligaments and tendons enter bones at the entheses, specialized structures with a transitional composition and architecture, which are relatively diverse depending on the location and biomechanical environment. Ligaments and tendons have a nonlinear mechanical response when subjected to tensile loads, and show viscoelastic behaviors such as creep and recovery, stress relaxation, and hysteresis. Their biomechanics has been investigated in numerous studies and shows a large variability depending on the biomechanical function of the tissue; in other words, their mechanical properties are influenced by skeletal maturation and aging, which involves a decrease in the water content and a stiffening of the collagen fibers due to cross-linking or due to exercise., SCOPUS: ch.b, info:eu-repo/semantics/published

This article presents data from the investigation of the thermal characteristics and mechanical behaviors of twelve different compositions of a polyurethane shape memory polymer (SMP). Each of the SMP compositions has a unique molar ratio of three monomers: (i) hexamethylene diisocyanate (HDI), (ii) N,N,N,N-Tetrakis(2-Hydroxypropyl)ethylenediamine (HPED), and (iii) Triethanolamine (TEA). The thermal characteristic datasets for each composition include the glass transition temperatures, as obtained from differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA), and the thermal degradation thresholds, as found from thermogravimetric analysis (TGA). The mechanical behaviors of the SMPs are represented by the failure stresses and strains, as obtained by cyclic tensile testing and failure testing, respectively. The interpretation of these measurements as well as a discussion of the potential usage of candidate SMP compositions for medical devices can be found in the companion article by Kunkel et al. (2018) [1], Synthesis and characterization of bio-compatible shape memory polymers with potential applications to endovascular embolization of intracranial aneurysms.

Magnesium alloys are the lightest known structural material and have been very attractive for usage in marine and transportation industry (for its weight savings and payload increase), and also for its portability in hand-held devices. It is recyclable and one of the most abundant metal. Lately, it has gained attention for its biocompatibility, and also its biodegradable properties depending on the alloying elements. They can be used as a biomaterial in various applications from heart stents to implant screws and fixtures. In this work, amorphous magnesium alloys have been processed, based on its glass forming ability, by various techniques in order to obtain its amorphous state, and the microstructure are characterized by thermal analysis, X-ray diffraction and electron microscopy. Their mechanical properties are also presented. High temperature tensile tests show similar strength to room temperature strength, while the total failure strain is significantly increased from around 0.5% to 10%., Sponsors: A3 Foresight Program by JSPS, NSFC, NRF; Thailand's Office of the Higher Education Commission; Chiang Mai Univ., Fac. Sci., Mater. Sci. Res. Cent.; Chiang Mai Univ., Fac. Sci.,; Nanoscience Nanotechnology Res. Cent.

Mg67Zn28Ca5 bulk metallic glass reinforced with 0.66-1.5vol% of nano alumina particulates were successfully synthesized using disintegrated melt deposition technique. Microstructural characterization revealed reasonably uniform distribution of alumina particulates in a metallic glass matrix. The reinforced particles have no significant effect on the glass forming ability of the monolithic glass matrix. Mechanical characterization under compressive loading showed improved micro hardness, fracture strength and failure strain with increase in nano alumina particulate reinforcement. The best combination of strength, hardness and ductility was observed in Mg/1.5vol% alumina composite with fracture strength of 780MPa and 2.6% failure strain.

The initial part of the uniaxial stress versus strain response in compression can be described in terms of an undamaged modulus, Eo, a peak stress, sigma(m) (a failure stress), and a strain at the peak stress, epsilon(m) (a failure strain). Sigma(m) increases in proportion to Eo and epsilon(m) is approximately constant with changes in temperature and strain rate for all of the composites considered. In addition, sigma(m) increases in proportion to Eo(exp 1/2) and epsilon(m) is proportional to 1/Eo(exp 1/2) for larger values of Eo for some of the composites. Brittle fracture is often, but not always, observed for the larger values of Eo. These results suggest two separate failure modes, and possible mechanisms for each mode are discussed.