Objectives: To evaluate the micro-tensile repair bond strength between aged and new composite, using silane and adhesives that were cured or left uncured when new composite was placed. Methods: Eighty Filtek Supreme XLT composite blocks and four control blocks were stored in water for two weeks and thermo-cycled. Sandpaper ground, etched and rinsed specimens were divided into two experimental g...

Heat-treatment in lithic technology refers to the controlled heating of quartz-rich, brittle, elastic lithic materials in order to reduce fracture toughness and improve knapping qualities. Successful heat-treatment reduces the point-tensile strength of many varieties of micro-crystalline quartz, including chert, without perceptibly altering any of the other properties with regard to fracture. T...

Tensile test on smooth and circumferentially notched specimens, systematic observation of fracture surfaces and large deformation finite element analysis were conducted to understand the deformation and failure behavior of a magnesium alloy (AM60). The plastic deformation is considered to be dominated by twining mediated slip. The tensile properties were not sensitive to the strain rates applie...

The strain rate effect on the tensile behaviors of a high specific strength steel (HSSS) with dual-phase microstructure has been investigated. The yield strength, the ultimate strength and the tensile toughness were all observed to increase with increasing strain rates at the range of 0.0006 to 56/s, rendering this HSSS as an excellent candidate for an energy absorber in the automobile industry...

A fracture analysis of highly loaded particulate reinforced composites was performed using laser moire interferometry to measure the displacements within the plastic zone at the tip of an advancing crack. Ten castings were made of five different particulate reinforcement-aluminum alloy combinations. Each casting included net-shape specimens which were used for the evaluation of fracture toughne...

Cracked and un-cracked Brazilian disc specimens subjected to diametral compression were used for conducting fracture toughness and tensile strength experiments on a polymer concrete (PC) material. The value of mode I fracture toughness (KIc) was determined from the center- cracked Brazilian disc and the indirect tensile strength (σt) was obtained from the un-cracked Brazilian disc specimen. The...

It is common practice in industry to monitor hydraulic fracturing jobs by picking major, micro-earthquake events in seismograms whose source locations form a spatial pattern used for interpreting induced fractures. Surprisingly, controversy still surrounds the interpretation of these scattered, discrete events. Many authors conclude that hydraulic fractures are generated by shear failure events...

Using natural hemp fibers to reinforce the tensile characteristics of polymer matrix composites is investigated in this article. The fibers were applied to the epoxy matrix in unidirectional and hybrid tissue forms. After preparation of standard tensile stress test specimens via manual layup, the standard tensile test was done.  Young’s modulus, ultimate tensile stress, and the amount of absorb...