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Abstract

The main advantage of condition monitoring by analyzing vibrations on rotating machines is the possibility of detecting faults before a failure occurs leading to the unplanned stoppage of a machine.

The unbalance defect is the most common and most frequently encountered cause of vibration, it is also one of the main causes of reduction in the life of machines and it constitutes one of the main risks for Security.

This paper is devoted to the experimental study of the two types of unbalance defects, their different vibratory signatures and how to differentiate their vibratory behavior from other mechanical faults which manifests itself by the presence of a peak at the rotational frequency in the case of combined faults.

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Abstract

The main advantage of condition monitoring by analyzing vibrations on rotating machines is the possibility of detecting faults before a failure occurs leading to the unplanned stoppage of a machine.

The unbalance defect is the most common and most frequently encountered cause of vibration, it is also one of the main causes of reduction in the life of machines and it constitutes one of the main risks for Security.

This paper is devoted to the experimental study of the two types of unbalance defects, their different vibratory signatures and how to differentiate their vibratory behavior from other mechanical faults which manifests itself by the presence of a peak at the rotational frequency in the case of combined faults.

Restricted access
Pollack Periodica
Authors:
Muhammad Safa Al-Din Tahir
,
Shakir Sakran Hassan
, and
Jumaa Salman Chiad

Abstract

The commercially available and research-developed positive-type ankle joints do not provide eversion and inversion movements and are limited to dorsiflexion and plantar-flexion. The aim of the research is to create an ankle joint that is simple to install, low in cost and closes in performance to the biological joint. The passive ankle joint is designed to perform dorsiflexion, plantar-flexion, eversion, and inversion movements. A biomechanical test was performed to find the similarity between the functions of the engineered ankle joint and the biological ankle joint. The conclusions show, the designed ankle joint on the simplicity of its structure and components, has come close to the biological function of the ankle in terms of angles.

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Pollack Periodica
Authors:
Muhammad Safa Al-Din Tahir
,
Shakir Sakran Hassan
, and
Jumaa Salman Chiad

Abstract

One form of energy storage in spring is applying a bending moment and converting it into tilt at the head of the spring as strain energy. The relationship between them is the lateral stiffness of the spring. The aim is to find a mathematical equation for the lateral stiffness of the spring and the effect of the length of the spring on the behavior of stiffness.

The mathematical model is created according to Castigliano’s second theorem. A simulated model of a conical spring is built using a Solid Work program. The theoretical results are compared with the mathematical model for the same conical spring.

Results of both theoretical and simulated models evinced a linear behavior of lateral, while an exponential relationship between the length of the spring and the lateral stiffness is indicated. The difference between theoretical and simulated models is not exceeded 3.2%, which indicates the acceptability of results.

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Pollack Periodica
Authors:
Klodian Dhoska
,
Drakuli Lumi
,
Anis Sulejmani
, and
Odhise Koça

Abstract

This research work has been focused on estimation of the measurement uncertainty for different steel reinforcement bars. The investigated material was HRB400 steel reinforcement with approximately diameter 16 mm and length 500 mm by using uniaxial tensile testing device. International standard ISO 6892: 2016 and guide for measurement uncertainty have been implemented an accurate method to determine the measurement uncertainty of HRB400 steel reinforcement bar measurements. The results of expanded uncertainty for 569.47 N/mm−2 correspond to 0.76 N/mm−2, which fulfil the international standard requirements. This accurate method can be used in most of the accredited laboratories as inspection services of steel reinforcement bar by using uniaxial tensile testing device at good accuracy.

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Abstract

Because of thin wall thicknesses and closed bottom ends of the extruded aerosol can, the necking limit analysis needs intensive investigation. The numerical analysis of the necking process of 0.45 mm thickness pure aluminum aerosol can was carried out. The result indicated that the length of the aerosol can wall, which is not fixed by the bottom die and the angle of inclination of necking tools are important factors that affect the development of deformation boundary limits due to plastic instability of local buckling. The fraction of taper angle of tool becomes more series parameter while necking at larger free length and it needs more concentration. Instead, the ratio of necking tool displacement to the total free length to initiate buckling was increased while increasing free length.

Open access
Pollack Periodica
Authors:
Fahad Mohanad Kadhim
,
Emad Zuhair Gheni
,
Athmar Thamer Naiyf
, and
Muhammad Safa Al-Din Tahir

Abstract

The objective of this study is to simulate material selection for fabricating hip joint prostheses from light-weight, low-cost materials which are also strong and durable. In this study, Co-Cr alloy CoCrWNi (F90), stainless steel ASIS 410, and titanium alloys (Ti6Al4V) material selection as the potential candidate for the suggested implant to manufacture a joint that is characterized by lightweight, low cost, does not react chemically with the human body and can bear the weight of the patient without mechanical failure. With this study, it was concluded the stainless steel ASIS 410 was selected as the best material selection since it passed engineering analysis, acceptable weight, and low cost compared to other proposed materials.

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Abstract

China has a lengthy and glorious history spanning thousands of years. Traditional dwellings represent distinct regional cultural origins, and different forms of housing constructions have arisen as a result. However, traditional dwellings preserve area culture and specific life memories as a fundamental component of rural life. From the perspective of conventional dwellings, this paper takes the representative Manchu folk houses in Northeast China as an example. It discusses the architectural structure, appearance style, and overall style of Manchu folk dwellings and the cultural dimension of architecture and its distinctive value under the impact of regional culture.

Open access

Abstract

Building Information Modelling (BIM) involves management efforts, tools and applications for enhancing information flow and, therefore, productivity of projects; adoption of BIM and the increasing use of digital technologies (e.g. data centers) in construction and operation of buildings, as well as in maintenance can transform the way how the industry works. Telecommunication cabinets equipped with large number of components of different types are inevitable parts of data centers having a significant influence on the efficiency and the reliability of data centers. Since the layout of equipment inside telecommunication cabinets is crucial in data centers and the ideal location of equipment inside each cabinet can be unique, an algorithmic and automated process is necessary for the cabinet façade scheme design; manually created diagrams can lead to errors. Furthermore, precise and up-to-date pieces of information about the special layout of equipment in each cabinet are also important for the further operation and maintenance. As an answer to this challenge, a BIM-based approach and method are presented in this article that can result in significant cost savings. When designing data centers, special attention must be paid to the location of telecommunication cabinets, the design of cable routes, and the layout of equipment inside. The novel cabinet family for BIM technology-based method has been developed for the improvement of data center design. Cable trays plug-in can lead to higher quality and efficiency of construction and the facility management as well.

The main goal of the case study: optimization of the design process of structured cabling systems (SCS) in data centers (DC) using new additional BIM capabilities.

The novel dynamic cabinet family have several distinctive features:

  • the ability to select in the properties which equipment will be inside the cabinet and which unit will occupy;

  • possibility to change and add equipment inside the cabinet;

  • creation of cabinet façade scheme based on equipment inside the cabinet;

  • automatically created specification;

Cable tray plug-in can improve and automate the design process in the following areas:

  • place trays depending on the installation method (wall, floor, ceiling);

  • place elements of the trays (hangers, consoles, racks) in a user-defined interval;

  • place tray connectors based on selected connector type and tray type at user-selectable spacing;

  • adding a tray cover and a partition in the tray properties;

  • automatically created specification of all cable trays elements.

The model created in BIM can be used for further operation and maintenance. To reach it, each of the elements or groups of elements contains a unique number that allows to bind its parameters and geometry for further export and use in the production model.

Open access

Abstract

The aim of this study is the manufacturing analysis of five spur gear pairs where the initial geometric parameters are the same only the pressure angle is different. Firstly, the gears must be designed and modelled. After that, I analyse the modification of this geometric parameter for the manufacturing parameters of the pinion and the gear in the case of gear cutting by module disc milling cutter. Using this technology the one tooth cutting can repeat from tooth to tooth in the function of the number of teeth. I would like to find correlations between the pressure angle and the manufacturing parameters. For this purpose, I define the initial technological parameters and calculate necessary technological parameters for the manufacturing process in a general way. I also define the manufacturing parameters for the given gear geometries. This analysis is practical and theoretical at the same time since the results and the process can help the manufacturing engineers to develop the gear manufacturing processes and applying my results for similar manufacturing problems.

Open access