Browse

51 - 60 of 3,767 items :

  • Mechanical Engineering x
Clear All

Abstract

This paper confers to compare the behavior of AZ91E, AZ91E with 2 wt. % plain and surface modified alumina reinforced composites under different loading conditions. The composites were prepared and specimens were cut in accordance with standard procedures to conduct impact and fatigue tests. Surface modified alumina reinforced AZ91E magnesium based composites resulted in improved impact and fatigue strength because of good interactions between the matrix and reinforcement. The results are discussed.

Abstract

A method for calculating the ultimate true stresses arising in the walls of shells of revolution in the area of uniform plastic deformation is developed in the research. In order to derive the stability loss for the plastic deformation process the criterion of maximum load is taken as the basis, simple differential equations were solved. It has been shown analytically that the level of the boundary true stresses is much lower when the values of the principal stress ratios approach to 2 or 1/2 compared to the adjacent stress states.

Abstract

The purpose of this technical note is to present a method of analysis of a joint made using a single row of bolts, typical of a bolts around the edge of a closure plat or a simple bracket. Classical analysis methods are applied to the joint subjected to combinations of both in-plane and out-of-plane loads and moments. An analysis of loads and stresses in a single bolt is developed. The note brings together a number of concepts and links them into a practical design analysis process that is applicable for many cases of joints made with a single bolt or a single line of bolts and are adequate to demonstrate the structural integrity of the joint. In some cases finite element methods may be more appropriate, and the methods discussed can be used in the validation process.

Abstract

The high efficiency of turbocompressors makes them ideal for supplying larger mines with com-pressed air. As the gas flows through the compressor, the pressure increases, generating a large amount of heat. This heat needs to be removed, and this is usually achieved through cooling towers and it ultimately escapes into the surroundings as waste heat. This article aims to study the recovery and possible use of this waste heat.

Abstract

The heat exchangers are used to heat or cool the material streams. To calculate the heat exchanger, it is important to know the type of heat exchanger and its operating characteristic. This characteristic determines one of the key variables (e.g., F, NTUmin, or θ). In some special cases, it is not necessary to know its operating characteristic to calculate the heat exchanger. This article deals with these special cases. The article also contains a general dependency that allows checking the key variables related to a given heat exchanger.

Abstract

In this work, the authors give an overview of the advancement of industrial robots and show the mechanization of welding processes, step by step. As manual welding is a physically exhausting professional work, engineers have sought to improve work conditions since the industrial revolution. Unfortunately, even today, many procedures can only be performed manually. In the welding process, the highest level of mechanization is represented by the use of robotics. The entrance of Robots in the history of welding is recent, though their spread and development are rapid.

OPEN ACCESS

Abstract

Today’s architectural and civil engineering design is almost inconceivable without collaborative tools. Building Information Modeling supports this with a set of collaboratively usable data. The roots of this concept go back in the past, thus the present paper attempts to depict some of the milestones in its evolution.

Abstract

The paper deals with stress and reliability calculation of a gas pipeline straight section buried in a ground (elastic foundation) loaded by heating and internal overpressure. Mathematical derivation of relations necessary for reliability calculation of the pipeline section by stochastic approach is also included in the paper. Resulting values are obtained by software Anthill using the Monte Carlo method. Input random parameters of the examined pipeline section are shown by bounded histograms.

Abstract

There are two concepts in the title that can be seen as “foreign” to the usual technical language. Both can have several meanings and thus we adapted them “flexibly” to the current needs. One way to understand the term “management” is through its functions: planning (defining purpose and means), organizing (defining tasks and methods), and direction (guidance, controlling), inspection (testing, comparing). It can also mean among other things, standpoint, circumstance, respect, or even character. Regarding the expression “damage management” the intended meaning here is reducing or to preventing damage to the tool, also improving the resistance of the tool material to damage, which besides material selection issues also has design, technology and operational aspects. This article gives an overview of some of these.

Abstract

The objective of these analyzes is to evaluate the behaviour of bearing cage in operation and to determinate the safety factor towards to yield and ultimate strength of structure, when cage is under load. Safety factor can be defined as force needed to achieve yield or ultimate strength divided by operation force given from dynamic simulation. Second analyze was based on pressing of whole cage in radial direction to determinate radial pressing force needed to achieve yield and ultimate strength.