The Mode I and II Interlaminar Fracture Toughness (IFT) of Vectran/Epoxy composite material were investigated using the Double Cantilever Beam (DCB) 4 End Notched Flexure (4ENF) methods, respectively. Due to relatively low compressive strength Vectran (<10% its tensile properties), specimens hybridised by over wrapping with T800s/M21 prevent failure during testing. Experimental results then sim...

Various effects on the room-temperature mechanical properties of TiCr2-base alloys have been assessed in efforts to improve the toughness of Laves phase intermetallics (AB2). Systematic studies were performed on: (i) single-phase stoichiometric and nonstoichiometric TiCr2, (ii) TiCr2-base ternary Laves phases, and (iii) two-phase binary alloys containing TiCr2. In order to make quantitative com...

A ``mutual integral'' approach is used to calculate the mixed-mode stress intensity factors for a free-edge delamination crack in a laminate under tensile loading conditions. This ``mutual integral'' approach, for generalized plane strain conditions, is based on the application of the path-independent J integral to a linear combination of three solutions: one, the problem of the laminate to be ...

Indentation techniques for assessing fracture toughness are attractive due to the simplicity and expediency of experiments, and because they potentially allow the characterization of both local and bulk fracture properties. Unfortunately, rarely have such techniques been proven to give accurate fracture toughness values. This is a concern, as such techniques are seeing increasing usage in the s...

Mechanical behaviour of unsaturated polyester resin used for the composite materials has been studied to determine various important parameters, such as tensile and compressive, single edge-notch tensile fracture toughness, flexural properties and fracture energy. Fracture toughness, KIC, and fracture energy, GIC, obtained for the polyester resin lie between the typical values for epoxy resins ...

Oxide Dispersion Strengthened (ODS) and TZM molybdenum have excellent creep resistance and strength at high temperatures in inert atmospheres. Fracture toughness and tensile testing was performed at temperatures between -1 50°C and 450°C to characterize 6.35 mm thick plate material of ODS and TZM molybdenum. A transition from low fracture toughness values (5.8 to 29.6 MPaJm) to values > 30 MPaJ...

Composite wind turbine blades may experience interlaminar damage, including adhesive failure, cracking, and fracture from manufacturing or external fatigue load. Among these, the failure of joints is critical. Therefore, it important to identify mechanism in between spar cap–shear web trailing edge composite blades. We calculated toughness through Mode I, II, Mixed-mode tests for quantitative a...

The fracture toughness at the bi-material interface of layered test pieces is determined using digital image correlation (DIC) as part dynamic shear tests. High-strain-rate tests are conducted on a three-layered bonded piece comprising central aluminum layer with PMMA resin layers. When crack sufficiently shorter than bonding length, mode II appears aluminum–PMMA interface; otherwise, I and fra...

Microencapsulated dicyclopentadiene (DCPD) healing agent and Grubbs’ Ru catalyst are incorporated into an epoxy matrix to produce a polymer composite capable of self-healing. The fracture toughness and healing efficiency of this composite are measured using a tapered double-cantilever beam (TDCB) specimen. Both the virgin and healed fracture toughness depend strongly on the size and concentrati...

Studies of bone have determined multiple toughening mechanisms slowing the propagation of a crack. These toughening mechanisms contribute to the fracture toughness of bone in life, making their activities of clinical interest. The primary standard methods for measuring bone fracture toughness use a single-notched compact type specimen (CT) or single-notched bending specimens in four-point (SN4P...