Specification of cross nonlinear vibration Of viscoelastic affective bar

this paper presents a solution of non-linear viscoelastic bar systems transversal vibrations problems in presence of biological factor. Governing differential equations were built, then analytical expressions of the solution of this equations were found, which describe transversal vibrations of a thin finite length bar

Numerical study of the use of Non-destructive Impact Test methods for the exam of integrity of concrete piles

This research includes a numerical study using Finite Element Method aims to evaluate the ability and accuracy of using Non-destructive Impact Response Method in the assessment of length and cross-sections of intact concrete pile (not deformed) in both time and frequency domains. Therefore, an appropriate numerical model depends on the modeling of both impact force (impulsive load) and distributing medium (pile + soil) and insert them in computing software ABAQUS was carried out. The numerical model was verified corresponding to field measures obtained from literature review and the results showed good agreement between measures and numerical results. Furthermore, the model was applied on a typical example in order to study vibration distribution in the pile due to impulsive load applied on pile top. Mechanical response curve of intact pile was obtained. Then, both of length and cross-section area of the pile were determined. Finally, parametrical study of most important factors (stiffness of soil surrounding the pile and length of pile embedded in the soil) effect on vibration distribution resulted from impulsive load applied on pile top. The parametrical study was carried out in two domains; first one was time domain depending on the direct analysis of particle displacement and velocity and the second was frequency domain depending on analysis of pile mechanical response curve. The results of this research enables to use the proposed numerical model to numerically obtain the time history of particle displacement and velocity in addition to the curve of mechanical response computed in the pile top and forms reference diagrams which is used later to compare with similar diagrams resulted from field test of executed piles. As a result, pile integrity test and detecting of defects in the piles if any. In addition, the limits of the use of both analysis methods adapted in research and choose the best between them according to the case study.

Study and Evaluation of Mechanical Vibrations Using Computer

Machine developing aimsto improve its velocity, capability and production,this is accompanied by increase of Mechanical side effects and the dynamical loads between the Machines elements and parts, that may conduct to rise the Mechanical vibrations and may cause a lot of damage in these machines, and cause negative effects on the environmentaround these machines, the study of Mechanical vibrations has a significant importance for engineering and technical students, to have knowledge of Mechanical vibrations that may arise in the machines under design process, or to study the mechanical vibrations resulting in the machines under use to isolate these vibrations and attenuate of its negative effects, for that we introduced an simulation program to show and illustrate a method to simulate some mathematical models representing some of possible types of vibrations, and to determine the most important parameters that describe the different vibrations motions, we choose an suitable programing language to merge this simulated models with an illustration and learning texts and drawings and animations in one executable application, this application show the models and the results in simple and very clear manner, and show the results in high resolution comparing with other programing languages.

A study of the possibility tomodifying some Properties of Unsaturated polyester Resin Compounds by adding Rubber materials

This paper is targeting towards studying on the possibility to modify some properties of unsaturated Polyester compounds by adding rubber materials in order to improve its flexibility property. For this target, Waste of cars' tires was used in two forms powder and pieces, and the liquid rubber Styrene-butadiene was used as another type of rubber. After that the modification was detected by measuring the possibility of the resulted compound materials to absorb vibration power, and reduce the noise that is produced by eccentric crankshaft circulation at different rotating speeds, (300, 500, 700) rpm. Test results demonstrate that there will be Modification in the construction of the compounds at low rotating speeds (300 rpm). On the other hand, it demonstrates different results at high rotating speeds.

Specification of cross nonlinear vibration of an elastic effective bar

The goal of the presented research in this paper is finding a unified way to solve cross vibration problems in nonlinear elastic fields with a biological factor. We obtained the equations of cross vibration for elastic systems by using known mathematical models, and then we solved the nonlinear cross harmonic vibration problem for a finite length of effective bar.

Specification of Longitudinal Nonlinear Vibration of Viscoelastic Affective bar

The main goal of the presented research in this paper is to find a unified way to solve longitudinal vibration problems in nonlinear viscoelastic media with a biological factor and solve the problem in a bar of finite length.

Propagation of longitudinal waves in biological media

The main goal of the presented research in this paper is to find a general way to solve longitudinal vibration problems. This way must solve these problems in nonlinear elastic bar systems with a biological factor. We applied longitudinal vibration equations in a nonlinear elastic bar with biological factor, the bar material was taken non-linear. and solve the problem in a bar of finite length.

A Model to Identify and Prioritise the Causes behind Losses in Company profit: Application Example

A production process includes several sub-processes (working areas) that are responsible for performing the different tasks required to accomplish the mission of the process. Thus, it is important to avoid a shortage of resources, unplanned stoppages and idle times that may arise. The problem addressed in this paper is: How should maintenance be considered in conjunction with plant activities, such as production, quality and personnel competence for easily and effectively identifying and quantifying company losses in profitability and eliminating underlying causes? In this paper, the interactions between major working areas have been introduced and discussed. The major result achieved in this study is the development of a new model (Maintenance Function Deployment (MFD), for an easy and effective identification and quantification of company losses in profitability. Four matrixe have been used for developing MFD model for effectively integrating maintenance with production, competence and quality. An application example is conducted to demonstrate the possibility of applying the model and its potential for enhancing production processes profitably. The main conclusion is: applying MFD gives an enormous opportunity to continuously maintain the quality of the working areas under consideration, which makes MFD one of the company s objective driven tools for enhancing its profitability and competitiveness.

The Study of the Effect of Mechanical Parameters in D.C. Crane Mechanism on the Quality of Transient States

The effect of two - mass system factors on the quality and quality of transient states , particularly the effect of mechanical rigidity has been studied in this research . Besides , mathematical expression which can calculate the optimal value of rigidity and provide the minimum extent of electromechanical vibrations have been obtained . Characteristics and schematic diagrams that prove the effect of mechanical rigidity on the behaviour of the transient state are illustrated . These methods help to improve the performance of automatic control systems in order to provide the minimum dynamic loads without reduction of the machine productivity.