statement of problem: resin composites are a common type of tooth coloured restorative materials. these materials are brittle and their major shortcomings are sensitivity to flaws and defects, low tensile strength, and susceptibility to catastrophic failure.the role of home bleaching agents on the fracture toughness of resin composites using four-point bending test is scanty. objectives: to com...

In this study, a novel numerical method is proposed for determination of mode-I interlaminar fracture toughness, GIc, in multi-directional (MD) double cantilever beam (DCB) specimens using fracture properties of unidirectional DCB specimens. Two factors, β and Dc are defined to minimize the undesirable effects on strain energy release rate. β describes the difference between maximum and average...

Leaves as the main photosynthetic organ of plants must be well protected against various hazards to achieve their optimal lifespans. Yet, within-species variation and the material basis of leaf strength have been explored for very few species. Here, we present a large dataset of leaf fracture toughness from a species-rich humid tropical forest on Barro Colorado Island, Panama, reporting both am...

The "EURO" fracture toughness data set is probably the largest comprehensive test for a single material. Previous analysis indicate that the steel in question is very homogeneous. Only one sub-plate appears to have significantly different fracture toughness properties that the others. Until now, no more sophisticated analysis regarding the homogeneity of the material has been performed. Recentl...

Bone fragility is a concern for aged and diseased bone. Measuring bone toughness and understanding fracture properties of the bone are critical for predicting fracture risk associated with age and disease and for preclinical testing of therapies. A reference point indentation technique (BioDent) has recently been developed to determine bone's resistance to fracture in a minimally invasive way b...

Natural and artificial materials including rocks and cement-based materials such as concrete and cement mortar are affected both physically and chemically by various natural factors known as weathering factors. The freeze-thaw process, as a weathering factor, considerably affects the properties of rocks and concrete. Therefore, the effect of the freeze-thaw process on the physical and mechanica...

The fracture toughness of SLG filled phenolic composites have been determined by short bar tests. It is expensive to prepare the samples for the tests. Therefore, it is necessary to develop a mathematical model that will predict the fracture toughness of particulate filled phenolic composites. Mathematical models for tensile strength, Young’s modulus are available but not for impact strength an...

Perfect graphene is believed to be the strongest material. However, the useful strength of large-area graphene with engineering relevance is usually determined by its fracture toughness, rather than the intrinsic strength that governs a uniform breaking of atomic bonds in perfect graphene. To date, the fracture toughness of graphene has not been measured. Here we report an in situ tensile testi...