An innovative scheme to prepare Prestressed double network (PDN) epoxies is presented using a judicious combination of tetrafunctional curatives that have similar molecular weights but different reaction kinetics. A diglycidyl ether of bisphenol A epoxy monomer was reacted stoichiometrically and sequentially with various molar ratios of an aliphatic polyetheramine curing agent and an aromatic c...

The rate-dependent fracture behavior of a 10-phr rubber-modified epoxy was investigated using double-cantilever-beam tests at various crosshead speeds. Dramatic rate effects were observed in the R-curve behavior and in the relationship between the applied energy-release rate and the crack velocity. Furthermore, a transition between fracture with toughening mechanisms operating (kinetic crack gr...

The mode II initiation fracture toughness of wood was measured by the three-point bend endnotched flexure (3ENF) test for various crack lengths, and the dependence of toughness on the crack length was analyzed by the four conventional methods of data reduction : elementary beam theory, Williams end correction method, and two compliance calibration methods. In addition to these methods, the comp...

The knowledge of load bearing characteristics and failure of material is very important for mechanical engineers. Various metallic, non metallic and composite materials are used in different application. In view of this, the main objective of the present work is to analyze the influence of Aluminum Oxide filler on Fracture Toughness properties of Chopped Strand Mat (CSM) E-Glass Fiber reinforce...

[1] Dry slab avalanches release by propagation of shear fractures in a thin, planar weak layer underneath a cohesive, stronger slab. This implies that a balance between shear fracture toughness and the shear fracture stress intensity factor fundamentally determines snow slab stability. Conventionally, fracture toughness is a material property and, for most materials, emphasis is on tensile frac...

In this investigation ‚the fracture toughness of A356 containing15%SiC composite was studied. Al/SiC composites have been considered because of their mechanical and erosion properties .Low fracture toughness in Al/SiC as compared with Aluminium alloys is one of its disadvantage. In this study at first A356 alloy was melted in a smelting electrical furnace then poured into the mould. A356-15% Si...

The more common use of instrumentation in impact testing opened up the possibility to apply fracture mechanics testing methods to polymers at moderately high impact rates. Tensile impact testing offers some advantages over the more common three-point bending and compact tension geometries. Most importantly the dynamic effects encountered at (moderately) high impact rates are less significant du...

The objective of the work was to investigate statistical analysis of fracture toughness of the glass fiber reinforced composites at different stacking sequences, strain rate and crack length. The glass reinforced vinylester composites prepared by hand layup technique with stacking sequences of 0/90, 45/-45 and chopped strand orientations. 3point bending for fracture toughness test for various n...

(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...