Stress analysis of standard truck chassis during ramping on block using finite element method

Haval Kamal Asker, Thaker Salih Dawood and Arkan Fawzi Said

The frame of the standard dump truck supports all types of complicated loads coming from the road and freight being loaded. So, the intensity and the strength of the frame play a big role in the truck's design. A frame of 6 wheels, standard dump truck has been studied and analyzed using ANSYS package software. The static intensity of the frame has been analyzed when exposed to pure bending and torsion stress, within two cases. First case is when the rear wheels zigzag gets over block (only one side of the chassis steps the block), and the second case is when both wheels gets over the block. Finite element model of a stress analysis of the vehicle chassis has been built using three dimension hyper elastic elements for the modeling. The results show important differences between the two case studies, especially in the torsion and deformations results obtained from the chassis model. Also, vibration modes have been analyzed during the loading conditions. The more damping ratio used, the more stabilizing of the stresses with respect to time.

Scour hole characteristics around a vertical pier under clear water scour conditions

A series of clear water scour experiments have been conducted in a tilting flume with a circular pier under different conditions of densimetric Froude number and inflow depths. Tests used a single pier of 50 mm diameter embedded in a sand bed of mean particle size d₅₀=0.365 mm. It was observed that the entire scour geometry (scour depth, length, width, area and volume) depended on the densimetric Froude number (F_D50) and inflow depth (h). On the basis of the obtained results, empirical equations are proposed for scour depth, scour length, scour width, scour area and scour volume. Scour hole parameters calculated from the proposed equations have been compared with those obtained from experimental results and are found to be very close to each other.

Axiomatic development of human psychophysiological stress indices using thermodynamics

Satish C. Boregowda, Rodney Handy, Olafur S. Palsson and Carol A. Boregowda

The present study involves development of an original quantitative methodology based on the principles of thermodynamics to define and measure human stress responses. The methodology combines five physiological measures (blood pressure, heart rate, finger skin temperature, facial electromyogram, and skin conductance level) to develop an Objective Stress Index (OSI). The study included forty-nine medical residents (28 males and 21 females). The physiological measures were taken under three conditions during the psycho physiological test profile. The Stress-Related Physical Symptoms Inventory (SPSI) questionnaire was administered during the course of the psycho physiological procedure. The Subjective Stress Index (SSI), a ratio of the severity of stress symptoms to the number of stress symptoms, was derived from the SPSI questionnaire. Without making any assumption about the distribution of the data, a nonparametric Mann-Whitney test was performed on the OSI and SSI data. The OSI results indicate that there was a significant difference in male and female stress responses. It is concluded that OSI in combination with the SSI will provide a quantitative framework for biomedical engineering researchers and practitioners to develop standards for measurement and evaluation of human stress responses.

Optimum design of switched reluctance machine using adaptive particle swarm optimization

Balaji M. and Kamaraj V.

This paper presents swarm intelligence based Adaptive Particle Swarm Optimization (APSO) technique to determine optimum design of Switched Reluctance Machine (SRM). In APSO technique, the inertia weight factor is made adaptive on the basis of objective functions of the current and best solutions to avoid premature convergence. The SRM design is treated as nonlinear multivariable constrained optimization problem. The objective functions for obtaining desired design are maximizing torque density, minimizing torque ripple and minimizing copper loss with stator and rotor pole arc as design variables. The potential of the proposed approach is tested on 8/6 four-phase, 5 HP, 1500 rpm SRM and the results are compared with those obtained from Genetic Algorithm (GA) and classical PSO technique. The results demonstrate that the proposed method is superior in terms of solution quality, accuracy, robustness and computational efficiency.

Dual converter controlled single phase matrix converter fed DC drive

D. Venkatasubramanian, S. P. Natarajan, B. Baskaran and S. Suganya

Abstract:

This paper presents an application of Single Phase Matrix Converter (SPMC) as a dual converter. Pulse Width Modulation (PWM) techniques are used to calculate the switch duty ratio to synthesize the output. Chosen PWM technique incorporating wave shaping is also used to ensure continuous supply current. Basic loads represented by R, R-L, motor loads are used in this investigation. The performances of chosen DC drive with SPMC based dual converter and SCR based dual converter are compared and analyzed. Selective simulation results are presented to verify the strategies developed. It is found that SPMC is a versatile topology.

Man Mohan and Puneet Kumar Singh

Abstract:

In distribution transformer design, main stress is to reduce core losses. To reduce core losses in distribution transformer cold-rolled grain oriented (CRGO) steel is preferred by manufacturers. Amorphous material has very less core losses compared to CRGO steel, therefore it is being seen as a good substitute of CRGO steel. Now-a-days some manufacturers are using amorphous material in miniature and medium size transformers in place of CRGO steel. The cost of amorphous core transformer is higher than the cost of CRGO core transformer. Here an effort is being made to reduce the cost of amorphous core distribution transformer by using a ‘CRGO-Amorphous’ core in place of amorphous core. A comparison is being presented here among ‘CRGO core distribution transformer (CCDT)’, ‘amorphous core distribution transformer (AMDT)’ and ‘Amorphous-CRGO core distribution transformer (AMCCDT)’, in terms of cost and efficiency.

Chlorite group minerals from the amphibolite facies metamorphic rocks of Krivaja-Konjuh Ultramafic massif in Bosnia and Herzegovina

M. Operta, S. Hyseni and S. Salihović

In amphibolite rocks, in the southern edge of Krivaja-Konjuh ultramafic massif, six samples are separated (from localities Stupčić I, Stupčić II, Pobilje, Donja Vijaka and Selište) in which occurrences of minerals of chlorite group are confirmed using optical tests. Mineral composition of samples of rocks is checked using x-ray analyses on the instrument of brand Philips with CuKa radiation with graphite monochromator. Chemical composition of mineral-chlorite in rocks was determined using electronic microsonde (ARL-SEMQ). Analyses of chlorite were calculated in accordance with recommendations of HYPER-FORM (S. Borg, A. Moggesie and E-Bjerg, 1991). Calculation of formulas of chlorite was done on the basis of 28 O and 36 (O, OH). In Bosnia and Herzegovina, minerals of chlorite group are very frequent and developed compounds in igneous, sedimentary and metamorphic rocks. Even though they are mentioned in numerous petrography and mineralogy papers, most of the authors of petrography papers describe chlorites as members of the mineral groups, and articles where more detailed selection or description of certain types of chlorite are given are more rare. Quantity of chlorite in amphibolite rocks in the area of Vijaka is variable. Chlorite in amphibolite rocks in the are of Vijaka occurs: In the shape of bands at contacts of amphibolite rocks with ultramafic rocks. In the crust of decaying of amphibolite rocks. As inclusions in corundum, garnets, amphiboles, pyroxene, plagioclase, and in u celyphitic rim of garnets as a product of retrograde metamorphism in the condition of hydrothermal metamorphosis.

Frequency offset estimation in coherent OFDM systems using different fading channels

Haritha T., S. SriGowri and D. Elizabeth Rani

Abstract:

The well known problem in an orthogonal frequency division multiplexing (OFDM) system is its sensitivity to frequency offset. Most of the coherent OFDM systems transmit pilot symbols on some of the subcarriers to estimate channel attenuation and also add a cyclic prefix (CP) to avoid intercarrier interference and intersymbol interference. An estimation algorithm based on the redundancy of both cyclic prefix and pilot subcarriers is proposed for the correction of frequency offset. If the frame timing is synchronised in advance, by considering the two kinds of redundancy simultaneously, the performance of the proposed hybrid algorithm achieves significant improvement under low SNR and short CP. As to high SNR and long CP, the performance of the hybrid algorithm is almost identical to that of CP-based algorithm. Some comparative simulations are given to illustrate the advantages of the proposed hybrid estimation scheme.

Evaluation of dynamic parameters of adhesively bonded steel and aluminum plates

Sourabha S. Havaldar, Ramesh S. Sharma, V. P. Raghupathy and Moortheesha Adiga

Abstract:

Weight reduction remains one of the key factors for various industries. Inevitably this will result in multi-material designs where the most appropriate material is selected for each part. A key enabler for such a multimaterial design is joining two materials with optimized weight which is balanced with the need to keep manufacturing costs down. Further, it is well known that these parts are subjected to dynamic load while in service conditions, and in order to evaluate dynamic parameters for design purpose an adhesively bonded dissimilar joint between Aluminium and Mild steel plates has been investigated experimentally through traditional “strike method” of  modal testing. FE simulation is also carried out and are compared with experimental results and found to be in good agreement.

Application of intelligent control techniques for global maximum power point tracking of solar photovoltaic system

Ramaprabha R. and Mathur B. L.

Abstract:

In this paper, a fuzzy logic based feedforward voltage method of global maximum power point (GMPP) tracking scheme is developed for the boost converter supplied Solar Photovoltaic (SPV) system.  With the developed realistic model of SPV array and boost converter the proposed controller has been simulated. The reference voltage is obtained from Artificial Neural Network (ANN). The ANN was trained for optimum values computed from Particle Swarm Optimization (PSO) technique. Fuzzy Logic Controller (FLC) is used to find the error in voltage and the output from FLC is fed to Pulse Width Modulator (PWM) to control the boost converter. Comparison studies have been made for Proportional plus Integral (PI) and FLC. From the simulation results, it is observed that the feedforward control strategy with fuzzy controller reduces error and it is a promising one with reference to GMPP tracking. Furthermore, it does not require any tuning of the parameters, unlike conventional PI controller, wherein the controller gain parameters needs to be changed when solar insolation changes.

Compatibility of 3-D turning diffusers by means of varying area ratios and outlet-inlet configurations

Normayati Nordin, Vijay R. Raghavan and Safiah Othman

Abstract:

Combined turning and diffusing is often associated with detrimental flow phenomena that contribute to losses induced by the very nature of its geometry. This paper aims to investigate the compatibility of using 3-D turning diffusers in improving pressure recovery and flow uniformity by means of varying area ratios (AR) and outlet-inlet configurations (W₂/W₁, X₂/X₁). There were three cases considered; (i) Case A (reference) - 2-D turning diffuser (AR=2.0, W₂/W₁=2.0, X₂/X₁=1.0), (ii) Case B- 3-D turning diffuser (AR=2.0, W₂/W₁=1.5, X₂/X₁=1.3) and (iii) Case C- 3-D turning diffuser (AR=4.0 W₂/W₁=1.5 and X₂/X₁=2.7). Inflow Reynolds Number (Re) approximately of 20 was applied. The experimental rig was set up with the diffuser models fabricated using acrylic. Particle Image Velocimetry (PIV) was used to acquire the velocity profile and visualize the flow structure in the diffusers. Digital manometer with resolution of 0.1Pa provided pressure values. Results show pressure recovery (C_p) of respectively 0.3, 0.1 and 0.5 gained for Case A, B and C. In terms of flow uniformity, standard deviations (s_u) of 2.04E-03, 3.14E-03 and 2.57E-03 were recorded respectively. There was a reduction in terms of recovery and uniformity when a 3D turning diffuser with an AR=2.0 was introduced. Whereas, the compatibility of 3-D turning diffuser with an AR=4.0 seems more promising. The results obtained in this study will be used to validate the CFD codes. The intensive CFD simulation by means of varying other geometry configurations in the event of different inflow Reynolds number will be carried out in future.

Development of the construction productivity estimation model using artificial neural network for finishing works for floors with marble

Faiq Mohammed Sarhan AL-Zwainy, Hatem A. Rasheed and Huda Farhan Ibraheem

Abstract:

Estimation of the productivity is an important task in the management of construction projects. The quality of construction management depends on accurate estimation of the construction productivity. In this paper, Multi-layer perceptron trainings using the back-propagation algorithm neural network is formulated and presented for estimation of the productivity of construction projects. Data used in the study are for residential, commercial and educational projects from different part from Iraq. These are used in training the model and evaluating its performance. Ten influencing factors are utilized for productivity forecasting by ANN  model, they include age, experience, number of the assist labor, height of the floor, size of the marbles tiles, Security Conditions, health Status for the work team, weather conditions, site condition, and availability of  construction  materials. One model was built for the prediction the productivity of marble finishing works for floors. It was found that ANNs have the ability to predict the productivity for finishing works with a very good degree of accuracy of the coefficient of correlation (R) was 89.55%, and average accuracy percentage of 90.9%.

Yaw Delali Bensah, Benjamin Agyei-Tuffour, Lucas N. W. Damoah and Johnson K. Efavi

Abstract:

In this work, a modified approach to melt compounding has been successfully developed to study the dispersion of kaolin particles in polyethylene and properties of polyethylene-kaolin clay composites. The process involved the use of melt compounding technique with vegetable lipid acting as a melting medium with the capability to enhance miscibility of the polyethylene with the kaolin which is necessary for strength improvement of the polyethylene-kaolin composite. Eight different compositional batches were formulated and cast at 300 ^oC. In all the thermal and mechanical properties as well the microstructure of the composites were studied. Comparisons of the composites with pristine polyethylene-lipid have shown an improved glass transition temperature (T_g) and the thermal decomposition temperatures as a result of changes in the chemical structure. Proportional kaolin additions did not change the crystallization temperature (T_c) of the blends as compared to the pristine polyethylene-lipid blend. Incorporation of 60 % kaolin by weight in the polyethylene-lipid matrix significantly improved the mechanical properties of the composites to its peak and an increased compressive strength of 2.0 to 8.7 MPa has been measured. Scanning electron microscopic (SEM) analyses shows the formation of a web-like entanglement caused by the dispersion of the kaolin particles in the matrix.

A case of similarity solutions for unsteady laminar boundary layer flow in curvilinear surface

Abstract:

In this paper, a study is made of the unsteady laminar natural convection boundary layer equations on a vertical curvilinear surface to establish necessary and sufficient conditions under which the similarity solutions are possible. The free parameter method is used to obtain similarity solutions. One of the cases of possible similarity solutions are discussed analytically and numerically.

An inexpensive shielded acoustic probe for pressure measurements near a radiating ultrasonic transducer

Peter W. Higgins and Corinne S. Lengsfeld

Abstract:

There is a need to detect the details of acoustic pressure fields in experiments near ultrasonic radiators being driven by high voltage signals which broadcast electromagnetic radiation, EMR, into the measurement media. Ultrasonic fields are being generated in fluids for the manufacture of unique materials through sonochemistry, and there is new interest in the degradation of biological molecules from such fields. Conventional field measuring sensors such as hydrophones, thermistors, and thermocouples are susceptible to contamination by the voltage signal emanating from the ultrasonic field generator when there is any contact with the measurement medium. Such EMR, entering the zone of measurement can be orders of magnitude greater than the voltage resulting from the measurement of the field itself. This work describes the design and characterization of a piezoelectric (PZT) planar disk encased within a separately grounded Faraday cage to act as a pressure field sensor. It is demonstrated that the separate grounding of this cage effectively eliminates the EMR contamination. Further, the work describes a calibration procedure incorporating a force beam to translate strain from a static load, and then from a dynamic load at the frequency of interest. Experimental measurements with this probe design show a near 80 % correlation to a theoretically calculated wave form using ray tracing to simulate the pressure field in the test cell.

Finite element analysis of thermal characteristics of annular fins with different profiles

M. Sudheer, G. Vignesh Shanbhag, Prashanth Kumar and Shashiraj Somayaji

Abstract:

Effect of chemical treatments on mechanical properties of jute fiber hybrid composite laminates

B. Sutharson, M. Rajendran, S. R. Devadasan and B. Selvam

Abstract:

Control design and simulation of distributed power-flow controller (DPFC)

P. Ramesh and M. Damodara Reddy

Abstract:

Geochemistry and economic potential of marble from Ikpeshi, south-west, Nigeria

Romanus Obasi and Fredrick Isife

Abstract:

Nigeria is endowed with varieties of valuable solid minerals and rocks. These minerals/rocks are capable of boosting the economic potentials of the country if fully exploited. Marble is one of such rocks that occur prominently in Ikpeshi area of Edo State, South-west, Nigeria Forty five (45) marble samples were subjected to geochemical, petrographic and physical analyses. Geochemical data show that the marble has variable geochemical characteristics; low dolomite CaMg (C03)2 (1.35-7.44%) and high calcite CaCO3 (82.78-95.61%) for those from other quarries and moderate dolomite (41.38-41.42%) and moderate calcite (61.03-61.58%) for those from the Golden Girl quarry. Physical tests indicate high tensile strength (17.342-31.550MPa), compressive strength (259.515-3892.73MPa) and shear strength (44.70-68.51MPa) respectively. Petrographical studies reveal that the marble contains calcite, dolomite, quartz, opaque mineral, actinolite, lead, feldspar and chlorite. Based on these characteristics, the marble from Ikpeshi is suitable as raw materials for manufacture of lime, drugs, toothpaste, paper and paint. It is also important in the production of livestock feed, electrical insulators, flooring tiles and terrazzo chips. The marble is unsuitable for cement production.

Diagnosis of faults using IMM estimator

M. Raghappriya, S. Kanthalakshmi and V. Manikandan

Abstract:

An approach to detection and diagnosis of multiple faults is proposed. It is based on Interacting Multiple Model (IMM) algorithm. The proposed approach provides means of detection, diagnosis of faults and state estimation. It is able to detect and diagnose the fault more quickly and reliably than other methods. In this paper the threshold values of various types of faults is also proposed. This is illustrated using an Aircraft example which has multiple failures-sensor, actuator and other component failures.