Zirconia/ veneer bi-layered components are extensively used in dental restoration technology to improve resistance of tooth’s surface from decay. The direction of the fracture propagation at the interface of zirconia and veneer is investigated in this paper. Finite element analysis is performed on a bi-material four point bend specimen in different geometries, and the fracture initiation angle is obtained using maximum tangential stress (MTS) criterion. The effect of specimen geometry on the fracture initiation angle is discussed. Because an interface crack may propagate through interface or kink into one of the materials, some comments are given to determine under which condition “interface de-bounding” will be happened.
An Eddy current damper uses magnets to suppress vibrations due to external excitations. These dampers also called electromagnetic dampers, have advantages of no mechanical contact, high reliability and stability, but require a relatively large volume and mass to attain a given amount of damping. The magnets respond to an external excitation field. Along with the construction of the damper, COMSOL software is used for analysis of the eddy current damper and got various results like magnetic flux density, eddy current intensity, velocity and acceleration of the moving magnet. For this a standard dimension of an automotive vehicle damper is used so that the prototype could be tested on a damper testing machine. The standard dimension is chosen to increase the adaptability, compatibility and to ease of testing the damper. After this task the response of damper under various loads is observed. Different materials of housing tube are taken to observe the effects of various parameters like flux density, current intensity and, of course, the damping capability of the prototype damper.
In the present world stiffeners are widely used to fulfill the requirement of high stiffness. Stiffened plates are used in most of the mechanical structures. In this paper free vibration analysis of eccentric and concentric stiffened isotropic plate with central stiffener and double stiffener has been studied and effect of various parameters such as boundary conditions, aspect ratio on non-dimensional frequency parameter of plate are investigated. Comparison of non-dimensional frequency parameter for eccentric and concentric isotropic stiffened plate with effect of number of stiffener at different mode shapes, aspect ratios and boundary conditions is studied using ANSYS parametric design language (APDL) code. A ten nodded element (SOLID 187) from ANSYS element library is used for the discretization of proposed stiffened isotropic plate. Convergence study of developed model with respect to the number of modes has been done and results are compared from the related available published literature. Non dimensional frequencies are higher for fully clamped boundary condition for eccentric and concentric stiffened isotropic plate in comparison to other boundary condition. It is also seen that non dimensional frequencies are increases in a moderate value for eccentric and concentric isotopic plate with double stiffener in comparison to the central stiffener.
The aim of this research is to investigate the impact of crumb rubber and Styrene-Butadiene-Styrene (SBS) on rutting potential of porous asphalt mixtures. Optimal binder content of control mix, 5% SBS, and mixtures containing 10%, 15%, and 20% of crumb rubber were determined using Cantabro Loss test. Dynamic creep, wheel tracking, draindown, and falling-head permeability tests were then carried out on specimens to examine rutting resistance, resistant to draindown, and permeability. SBS modified and 10% rubberized asphalt satisfied all the requirements of porous asphalt design criteria. They also have similar rutting performance, permeability. Except for rutting performance, 10% rubberized asphalt has the best performance. Instead, asphalt mixture containing 20% crumb rubber was the most mixture against rutting resistance.
One of the specimens to investigate the mode-I fracture toughness of rock and geo-materials is semi-circular bend (SCB) specimen. In general, initial cracks in rock test specimens are produced in two shapes: straight-edge cracks and chevron notches. The ISRM suggested SCB specimen has straight shaped notch. However, use of V-shaped (or chevron) notch in the SCB specimen is preferred because of some technical difficulties associated with making a sharp crack or creating pre-crack to conduct the experimental tests. In this paper, the minimum dimensionless stress intensity factor of cracked chevron notched semi-circular bend (CCNSCB) specimen is determined using finite element analysis with ABAQUS software. An analytical method, (i.e. Bluhm’s slice synthesis method) is used to verify the results. It is shown that a good agreement exists between the numerical data and theoretical results.
This paper presents a numerical analysis of free vibration of thin circular and annular plate using finite element method. The first five natural frequencies are presented for uniform annular plates of various inner-to-outer radius ratios, with nine possible combinations of free, clamped and simply supported boundary conditions at the inner and outer edges of plates. The accuracy of the method is established by comparing the results available in the literature. Results show that natural frequency parameter increases as the inner-to-outer radius ratio increases except in case of free boundary condition, for which it decreases with the inner-to-outer radius ratio. This result provides benchmark values that can be used to validate result obtained by other approximate approaches such as finite difference method, differential quadrature method and boundary element method.
Force measurement is very vital in various scientific applications and its precise measurement is very necessary for reliability of the measurement process. There are several types of simple shaped force transducers, which may range from ring shaped force transducers to cantilever type or beam type force transducers. Ring shaped force transducers are one of most commonly used type of force transducers are developed on the basis of theory of thin rings. Till today, some of the modifications of ring shaped force transducers have been reported, the present investigation discusses the development of elliptical shaped force transducer as a modification of ring shaped force transducers and its preliminary investigation on metrological characterization based on the calibration procedures according to standards ISO 376-2011. The force transducer has been developed for the nominal capacity of 20 kN and strain gauges have been applied over the optimum locations to minimize cross sensitivity. The force transducer is developed exclusively for static force measurement related applications to serve as a link in providing the traceability to the user industries and calibration laboratories or serve as force transfer standard. The force transducer has been evaluated for suitability as a precision force transducer with the help of the 50 kN Dead Weight force machine traceable to national standard of force. The elliptical shape force transducers are found to have comparable metrological characteristics as compared to other ring shape force transducers.