This paper discusses the use of fracture mechanics for the microstructure tailoring of a fiber reinforced Engineered Cementitious Composite (ECC) to achieve extreme tensile ductility at the composite scale. It demonstrates that fracture mechanics applied to control fracture phenomena at the micro and meso material scales can lead to suppression of fracture failure at the macro structural scale....

The onshore oil and natural gas industries of China have started a large-scale development when crude oil reserves have been difficult to recover. The stratum fracture modification is an indispensable measure to efficiently develop oil and gas fields. Hydraulic fracturing is the most important reservoir stimulation technique, but it is still faced with various problems such as the failure to fr...

An experimental evaluation of mixed mode fracture tests conducted on adhesively bonded wood specimens using a dual actuator load frame is presented. This unit allows the fracture mode mixity to be easily varied during testing of a given specimen, providing improved consistency, accuracy, and ease of testing over a range of loading modes. Double cantilever beam (DCB) type specimens made of south...

We introduce a lattice model able to describe damage and yielding in heterogeneous materials ranging from brittle to ductile ones. Ductile fracture surfaces, obtained when the system breaks once the strain is completely localized, are shown to correspond to minimum energy surfaces. The similarity of the resulting fracture paths to the limits of brittle fracture or minimum energy surfaces is qua...

The near-source energy released on a fault is estimated through the strain energy change and the fracture energy from the results of kinematic waveform inversion and dynamic modeling for two different types of earthquakes: a shallow crustal earthquake, the 2000 Tottori, Japan (Mw 6.6) earthquake, and an in-slab event, the 1999 Oaxaca, Mexico (Mw 7.5) earthquake. The procedure incorporates the s...

The performance of components produced by conventional route of a thermo mechanical process and those produced by continuous casting is interesting from different aspects of economy and technology. The performance of products in their service depends on their properties which are strongly influenced by production routes. In the present work the hardness, tensile and tensile-impact behaviors of ...

INTRODUCTION Osteoporosis represents one of the most frequent comorbidity among HIV patients. The current standard method for osteoporosis diagnosis is dual-energy X-ray absorptiometry. Calcaneal quantitative ultrasound can provide information about bone quality. The aims of this study are to compare these two methods and to evaluate their ability to screen for vertebral fracture. METHODS Thi...

Dynamic fracture in a wide class of materials reveals a "fracture energy" Gamma much larger than the expected nominal surface energy due to the formation of two fresh surfaces. Moreover, the fracture energy depends on the crack velocity, Gamma=Gamma(upsilon). We show that a simple dynamical theory of viscoplasticity coupled to asymptotic pure linear elasticity provides a possible explanation to...

Background: Surgery in the time of COVID-19 pandemic is a challenging issue while treatment of affected fracturepatients is inevitable. The present study summarizes the challenges that an orthopedic surgeon is confronting duringthe surgical treatment of fracture patients with concomitant COVID-19 infection.Methods: Demographic and fracture related data of 13 fracture patients ...

Microstructures, tensile properties and fracture energy of a friction stir spot welded polycarbonate (FSSW) were studied at varying rotational rates and dwelling time. The problem of common FSSW welding is the remaining of characteristic keyhole. This can act as a concentration place in mechanical tests. To order solve this problem authors took advantage of innovation for designing the welding ...