Mineralization is a typical strategy used in natural materials to achieve high stiffness and hardness for structural functions such as skeletal support, protection or predation. High mineral content generally leads to brittleness, yet natural materials such as bone, mollusk shells or glass sponge achieve relatively high toughness considering the weakness of their constituents through intricate ...

Thin film delamination can occur when the stored elastic energy per unit area in the film due to the residual stress exceeds the interfacial toughness. Telephone cord morphology is commonly observed in delaminating thin films under compressive stresses. Here, the biaxial film stress is partially relieved by film buckling in the direction perpendicular to the telephone cord propagation, and by "...

dried figs collected from various exporting companies (2,461 samples) and local stores (219 samples) were analyzed using reverse-phase high-performance liquid chromatography (rp-hplc) to determine and compare the incidence of aflatoxins, the effectiveness of the regulation limits and monitoring system to select non-compliant samples and the mean daily aflatoxin exposures. the incidence rates of...

The mode I fracture toughness as a function of crack length of medium density fiberboard (MDF), particle board (PB), and Douglas-fir (DF) were all measured using a new energy-based method. PB and MDF are examples of composites that develop fiber bridging during crack propagation, which causes their toughness to increase with crack length. Longitudinal cracks in DF also displayed fiber bridging ...

This paper aims to clarify the effect of steel fiber on the flexural toughness of the high performance concrete containing fly ash and nano-SiO2. The flexural toughness was evaluated by two methods, which are based on ASTM C1018 and DBV-1998, respectively. By means of three-point bending method, the flexural toughness indices, variation coefficients of bearing capacity, deformation energy, and ...

Graphene is the strongest and stiffest material ever identified and the best electrical conductor known to date, making it an ideal candidate for constructing nanocomposites used in flexible energy devices. However, it remains a great challenge to assemble graphene nanosheets into macro-sized high-performance nanocomposites in practical applications of flexible energy devices using traditional ...

(2005) Fracture behavior of polyetherimide (PEI) and interlaminar fracture of CF/PEI laminates at elevated temperatures. Abstract To investigate effects of environmental temperature on fracture behaviour of a polyetherimide (PEI) thermoplastic polymer and its carbon fibre (CF/PEI) composite, experimental and numerical studies were performed on compact tension (CT) and double cantilever beam (DC...

INTRODUCTION Bone fracture is a major concern for elderly because the toughness of aged bone becomes more susceptible to impact load.(6) It has been well documented that the post-yield behavior of bone determines the major part of the toughness of bone.(3,4) As a natural composite material, bone primarily comprises a hard mineral phase (mainly hydroxyapatite crystals) and a more compliant colla...

In this study, the fractal dimensions of failure surfaces of vinyl ester based nanocomposites are estimated using two classical methods, Vertical Section Method (VSM) and Slit Island Method (SIM), based on the processing of 3D digital microscopic images. Self-affine fractal geometry has been observed in the experimentally obtained failure surfaces of graphite platelet reinforced nanocomposites ...

Channeling cracks in brittle thin films have been observed to be a key reliability issue for advanced interconnects and other integrated structures. Most theoretical studies to date have assumed no delamination at the interface, while experiments have observed channel cracks both with and without interfacial delamination. This paper analyzes the effect of interfacial delamination on the fractur...