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Showing 1 to 20 of 60 for “"Mode II"”.
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Mode I and Mode II Measurements For Stiction Failed Micro-Electro-Mechanical Systems
… have constructed an apparatus to determine the Mode I, II, and III interfacial adhesion energies of MEMS devices failed on a substrate. Though our method is general, we are specifically focused on devices created using the SUMMiT V process. An apparatus has been constructed that has 8 …
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Fracture Characteristics of Asphalt Concrete in Mode I, Mode II, and Mixed-Mode
… above were used to develop and validate a new Mode II test for asphalt concrete. No previous literature was found that attempted to capture Mode II fracture energy in asphalt concrete, so a test was developed from an extensive review of Mode II tests in the fields of metal, plastic, and PCC. …
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Mode II fracture mechanics of moso bamboo for application in novel engineering materials
… has been increasing interest in its use as a modem construction material. In this study, as part of a larger project to characterize the mechanical properties of Moso bamboo for application in the production of structural bamboo products (SBP), end-notched flexure (ENF) tests and three-point …
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Fracture toughness determination and micromechanics of rock under Mode I and Mode II loading
… new experimental method for the determination of Mode II (shear) fracture toughness, KIIC of rock and compares the outcome to results from Mode I (tensile) fracture toughness, KIC, testing using the International Society of Rock Mechanics Chevron-Bend method.Critical Mode I fracture growth at …
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Effects of Voids on Delamination Behavior Under Static and Fatigue Mode I and Mode II
… or interlaminar failure is a serious failure mode observed in composite structures. Even partial delamination will lead to a loss of local stiffness, which can preclude buckling failure. Manufacturing process defects such as voids and fiber waviness degrade the fatigue life and delamination …
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Experimentation of Mode I and Mode II Fracture of Uni-Directional Composites and Finite Element Analysis of Mode I Fracture Using Cohesive Contact
… One of the most prevalent and limiting mode of failure within composite laminates is delamination, since it not only reduces a structures stiffness and strength, but can be very difficult to detect without the use of special non-destructive equipment. Industry testing organizations have …
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Investigation of the Effects of Geometry on the Efficiency of the Double Lap Joint of Unidirectional Fiberglass Composites
<p>The fracture toughness in shear mode (Mode II) has been studied for double lap adhesive joints where geometry of the joint is the major parameter. A unidirectional fiberglass - epoxy system was selected for experimental tests and theoretical analysis. Both rectangular and elliptical planform …
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An investigation into the deformation and tearing of thin circular plates subjected to impulsive loads
… mild steel plates fail with mode I (large ductile deformation), mode II (tensile-tearing and deformation) and mode III (transverse-shear) failure modes. The impulse is measured by means of a ballistic pendulum upon which the test plates are attached. During mode II and mode …
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Evaluation of efficiency of partial hybrid finite element method using composite laminates with crack
… also studied. The cracked composite laminate is modeled with three types of elements: 20-node three-dimensional sub-laminate partial hybrid elements are used in the local region where the stress gradients are expected to be high; 8-node degenerated partial hybrid plate elements are used in the …
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A study of brittle powder compaction using a combined discrete finite element approach
… media. Using the Finite Element Method to model the behaviour of each discrete element has resulted in the Combined Finite Discrete Element Method. This combination allows researchers to investigate the behaviour of assemblies of particles in which each particle need not behave in an …
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Dynamic Mixed-Mode Fracture of Bonded Composite Joints for Automotive Crashworthiness
An experimental evaluation of the mixed-mode fracture behavior of bonded composite joints is presented. Commonly used experimental techniques for characterizing the mode I, mixed-mode I/II, mode II, and mode III fracture behavior have been employed for the purpose of developing a fracture envelope …
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Measurement of delamination crack tip displacement in G/E laminates using scanning electron microscopy
… into a jig which allows the application of Mode I or II loads individually or simultaneously. The specimen is placed into the SEM and a series of photographs are taken from slightly ahead of the crack tip to approximately 800 microns behind the crack tip. The photos are subsequently enlarged …
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Half-Lap Cross Laminated Timber Pegged Joints
… load than the Austrian spruce specimens. Yield Mode II and V were the two identified failure modes, with Mode II occurring primarily in the Austrian spruce specimens and Mode V predominantly occurring in the yellow-poplar specimens. Connection yield loads were predicted using Yield Mode II and V …
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Understanding the correlation between wrinkle morphology, fracture and fatigue of plain woven CFRP laminates through mechanical and ultrasonic characterization.
… on interlaminar fracture toughness under both Mode I and Mode II loading conditions, along with the development of a novel ultrasonic characterization technique for wrinkle detection and quantification. In the first part of the study, a co-curing-based fabrication technique was developed to …
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Experimental and Numerical Methods for Characterizing the Mixed-Mode Fracture Envelope for a Tough Epoxy
… Fracture can occur in one of three different modes, or in some combination. Many practical adhesive joints fail in the mixed-mode region involving both opening (mode I) and shearing (mode II) displacements. Mode I fracture was evaluated with double cantilever beam (DCB) tests, mode II fracture …
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Mechanism of Fatigue Crack Growth at Polymer/metal Interface
… an Al/epoxy interface was examined under mixed-mode conditions. To provide different combinations of Mode-I and Mode-II conditions, a flexural peel (FP) technique was developed, which proved to be particularly useful for subcritical crack growth studies. Using this technique, fatigue crack …
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The effect of cooling rate on toughness and crystallinity in poly(ether ketone ketone) (PEKK)/G30-500 composites
… the effect of cooling rate on crystallinity and mode I and mode II strain energy release rates, G<sub>Ic</sub> and G<sub>IIc</sub>, respectively, showed that G<sub>Ic</sub> and G<sub>IIc</sub> values increase with increasing cooling rate. Comparison of the toughness values as a function of …
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Evaluation of bond between pavement layers: fracture mechanics approach
… that can be readily utilized in computational models in order to facilitate system optimization and linkage between material properties and field performance. This dissertation describes the development, application, and validation of three new fracture energy based interface bond tests …
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Using far-field measurements for determining mixed-mode interactions at interfaces
… is to develop a direct method to extract mixed-mode TSRs using only the far-field measurements. The first topic of the dissertation deals with extracting mixed-mode TSRs based on a combination of global and local measurements including load-displacement, crack extension, crack tip opening …
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Response and Failure of Adhesively Bonded Automotive Composite Structures under Impact Loads
… Based on the use of a modified drop tower, mode I, II, and mixed mode values for critical energy release rate were determined for a composite/epoxy system and used to create a fracture failure envelope. Because load measurements become erratic and unreliable at higher test rates, …
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