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.
In advanced modern turbines, the temperature of the turbine & apos; s first blade row which is called the turbine & apos; s hot part, increases almost as 1000?. These blades must operate for long periods of time. Since, the main failure reason of the parts operating under high temperature and cyclic loading conditions is fatigue as well as creeping phenomena, acquiring an accurate estimate of these blades & apos; lifetime under creeping and fatigue interactions is very necessary for theoretical and practical requirements. The fatigue of the first blade row of the micro turbine TRI60 is analyzed in this study. For the purpose of estimating the fatigue lifetime of turbine and motor, heat transfer of blades as well as thermal stress is analyzed at first via ABAQUS software. Consequently, a fatigue analysis under full cycle and within the interval of 2/3 v_max to v_max is performed using Smith-Watson-Taper algorithm and transient modal analysis via Fe-safe software.
There are literally several studies accomplished to predict the fatigue life of leaf springs but estimation of fatigue life of a parabolic leaf spring by using CAE tools has not yet been executed in the past. Parabolic spring is an important component in a vehicle suspension system. It needs to have excellent fatigue life and in today’s scenario manufacturers rely on constant loading fatigue analysis. The objective of this work is to perform the fatigue analysis of parabolic leaf spring by three different methods where CAE analysis is performed to observe the distribution of stress fatigue life and damage using Goodman approach. In this work, fatigue life of the parabolic leaf spring is determined as per SAE spring design manual and experimentally by testing on full scale fatigue testing machine. ANSYS is used for CAE solution for the prediction of leaf springs fatigue life considering stress theory. The fatigue life estimated by all three modes is then compared for the purpose of validation. The methodology used in this paper brings a practical approach to the professionals in the industries who are engaged for design of mechanical components.
This paper presents the free vibration analysis of stiffened isotropic plate by means of finite element method. Stiffeners are used in plates to increase the strength and stiffness. The effect of position of stiffeners on isotropic plate has been studied which involve the possible combination of clamped and free edge condition. The model has been discretized using a 20-node solid element (SOLID186) from the ANSYS element library. The natural frequencies are calculated using Block-Lanczos algorithm. The comparisons of stiffened plate with the available results are found to be in good uniformity. The effect of different boundary conditions, stiffeners location, thickness ratio, stiffener thickness to plate thickness and aspect ratio on the vibration analysis of stiffened plates has been studied.
Head injuries are among the dangerous injuries which are common in all sport types. In the present study, the dynamic response of a punch to the head of a Wushu fighter was simulated by modeling the human head in ABAQUS software. Moreover, the maximum displacement and the stress distribution in the helmet and head parts were analyzed by finite elements method. The obtained results showed a significant interval in the response of different tissues to the delivered blow. The maximum shear stress, normal stress and displacement in the helmet were 5.616 MPa, 5.755 MPa and 1.236 mm, respectively, while these magnitudes were respectively 3.199 MPa, 6.268 MPa and 0.0001867 mm in skull, 4.596 MPa, 3.691 MPa and 0.1180 mm in the head skin and 0.01098 MPa, 0.8779 MPa and 0.04993 mm in brain. The present model with its unique features can be a valuable and powerful instrument to gain a better insight into the injury mechanism for better diagnosing of injuries and to design protective helmets with higher efficiency and safety for various sport forms as well.
An analytical and numerical solution is developed for a transient heat conduction equation in which a plane slab is heated by a bimodal distribution beam over the upper surface. In laser heat treatment of steel few methods are used to produce a wider and nearly uniform average irradiance profile. This may be achieved by a bimodal (TEM11) shaped laser beam. In this paper, Green function method is employed to derive an analytical solution for thermal field distribution induced by laser forming process. Then 3-D finite element modeling of a slab in the ANSYS code is used to model the thermal field of laser forming with bimodal beam distribution. The results show that bimodal beam is useful for obtaining a uniform heat intensity distribution.