Mechanical properties of cortical bones related to temperature and orientation of Haversian canals

Abstract

The understanding of mechanical performances and microscopic failure mechanisms of cortical bones under service condition is necessary prerequisite of fracture prevention, which would support the development of bone tissue engineering and design of bionic bones. By using miniaturized horizontal in situ compression tester, the effects of both temperature and sampling orientations on the compressive strengths and fracture morphologies were investigated. The significant difference between fracture strengths and compressive strains at various temperatures indicated that the cortical bone was sensitive to temperature. Direct experimental evidences revealed the gradually fibrotic trend of fracture surfaces as a function of sampling orientation. Through the Haversian canals distribution analysis, the relationship between the distribution of Haversian canals and fracture path was established. Essentially, the competition between high density Haversian canals and stress concentration factor determines the initiation and propagation of cracks.

Angle‐ply orientation‐dependent failure behaviors of carbon fiber reinforced polymer laminates

“…Figure 1 showed the three‐dimensional model of CFRP laminates specimens with different angle‐ply orientations under uniaxial tensile load by a horizontal tensile tester 6,22 . The specimens were composed of four single‐layer plates, and the fiber directions of each layer are distinct.…”

Conventional Manufacturing by Pouring versus Additive Manufacturing Technology of β-Tricalcium Phosphate Bone Substitute Implants

“…The literature describes a decrease in the compressive strength of cortical bone depending on temperature and pressure applied orthogonally to the direction of the Haversian canals. At a temperature of 38.5°C, the compressive strength of compact bone decreases from 82.7 ± 11.3 MPa, measured in the direction of the Haversian canals, to 67.6 ± 10.9 MPa orthogonally [36]. Data on the compressive strength of human compact bone varies between values of 130 and 180 MPa [33,37].…”

In Situ Bending Reveals Simultaneous Enhancements of Strength and Ductility of Cortical and Cancellous Layers Induced by the Cartilage Layer

“…Composite bone structures consisting of cartilage layer and cortical and cancellous layers utilize the layered gradient structures and diverse compositions to realize the rigid-flexible coupling performances and excellent deformation resistances, which could effectively bear multidirectional static and dynamic loads . In actual, attributed to the hierarchical and ordered mineralized collagen fibrils and embedded hydroxyapatite structure, the cortical layer exhibit favorable resistance to deformation and high strength against fracture . Meanwhile, the articular cartilage is considered as a special connective tissue as no blood vessel, nerve, and lymphatic vessel exist in cartilage.…”

“…The existing investigations on the mechanical properties of cartilage and cortical layer mainly focused on the independent performances, including the toughness, friction, and wear properties of cartilage, crack propagation path, distribution of surface hardness and Young’s modulus, and strength and toughness of the cortical layer at different scales. , For instance, Fan et al studied the deviation rate between natural knee cartilage and polyvinyl alcohol hydrogel artificial cartilage under different compression conditions, Tertuliano et al prepared several pillars with various diameters to investigate the size effect-induced brittle-to-ductile transition of the cortical layer . Our previous studies also proposed a prediction approach of cross section fracture path of the cortical layer through establishment of nanoindentation array and investigated the mechanical properties of the cortical layer related to temperature and orientation of Haversian canals . The independent tests after peeling the cartilage layer or cortical layer are unable to quantitatively obtain the effects of the cartilage layer on the deformation resistance and mechanical properties of the composite bone structure .…”

“…1 In actual, attributed to the hierarchical and ordered mineralized collagen fibrils and embedded hydroxyapatite structure, the cortical layer exhibit favorable resistance to deformation and high strength against fracture. 2 Meanwhile, the articular cartilage is considered as a special connective tissue as no blood vessel, nerve, and lymphatic vessel exist in cartilage. Once injured, the cartilage is difficult to self-heal.…”