The morphology of injection moulded samples of polyamide-polybutadiene blends (85.15) with an average particle size of 0.3 pm was studied. The samples were fractured in a notched tensile test at crosshead speeds of 10m4 and 1 rns-’ and the structure of the deformation zone was studied using various techniques: polarized light microscopy, scanning electron microscopy, transmission electron micro...

The seismoelectric logging method is based on measuring the electric field generated by seismic waves in a fluid-filled borehole. Two kinds of electromagnetic (EM) fields can be generated within the formation and at the interface of formations. One is a stationary or local EM wave and the other is a radiating EM wave. In this paper, we make various fractured borehole models with artificial mate...

The Khushab anticline is located in the Zagros fold-thrust belt in the Lurestan. This anticline is affected by the Balarud fault zone, which is a part of Mountain Front Fault between the Lurestan and Dezful Embayment zones. Based on the measurement of the elements of fold style, this anticline is analyzed. According to these measurements, this anticline is a noncylindrical, asymmetrical and dis...

This study investigates the propagation of borehole Stoneley waves across heterogeneous and permeable structures. By modeling the structure as a zone intersecting the borehole, a simple one-dimensional theory is formulated to treat the interaction of the Stoneley wave with the structure. This is possible because the Stoneley wave is a guided wave, with no geometric spreading as it propagates al...

Bedrock fracture systems facilitate weathering, allowing fresh mineral surfaces to interact with corrosive waters and biota from Earth's surface, while simultaneously promoting drainage of chemically equilibrated fluids. We show that topographic perturbations to regional stress fields explain bedrock fracture distributions, as revealed by seismic velocity and electrical resistivity surveys from...

Microseismicity. stress, and fracture in the Coso geothermal field are investigated using seismicity, focal mechanisms and stress analysis. Comparison of hypocenters of microearthquakes with locations of development wells indicates that microseismic activity has increased since the commencement of fluid injection and circulation. Microearthquakes in the geothermal field are proposed as indicato...

This paper deals with the application of Cohesive Zone Model (CZM) concepts to study mode I fracture in adhesive bonded joints. In particular, an intrinsic piece-wise linear cohesive surface relation is used in order to model fracture in a pre-cracked bonded Double Cantilever Beam (DCB) specimen. Finite element implementation of the CZM is accomplished by means of the user element (UEL) feature...