ANALYSIS OF DYNAMIC INTERACTION BETWEEN FLEXIBLE BODY OF OVERHEAD CONTACT WIRE AND ACTIVE CONTROL PANTOGRAPH CONSIDERING VERTICAL BODY VIBRATION

The current collection system consists of a pantograph placed on the roof top of a trains’ vehicle and overhead contact wire supported by evenly spaced vertical holders which supply the current to the pantograph from the electric power grid. Most of the pantographs produce averagely good performances at low and medium speeds, approximately less than 250 km/h. However, at higher speeds, the response of the pantographs is distorted. Thus the stability of the current collection is in peril. In addition, due to vertical vibration of the car body during high speed, contact force variation occurs between the pantograph and overhead wire. Therefore, it is necessary to maintain the contact between pantograph and overhead wire. In this study, the multi-body dynamics analysis is used to model the flexible body of overhead wire. An excitation experiment is performed in order to determine the parameters of pantograph. With consideration of vertical body vibration, an active pantograph control is developed to eliminate the effect of vibration to contact force, reduce the maximum peaks and avoid contact loss

Maintenance and Physical Asset Management Issues in Project Commissioning

This study describes the review on maintenance related issues during design and construction stage within construction industry. The paper highlights the causes and errors made during design and construction stage and their impact during the operation/production/occupancy stage as well as the maintenance costs associated with it. The study identifies the mistakes in the working processes within design and construction stage leading to the errors that affect the durability, performance, reliability, maintainability, availability and safety of the systems. The paper presents a comprehensive review of the published literatures, journals, technical papers in the related areas in the construction field. The review highlights the new approaches and decision framework which link the designers and construction personnel that could reduce the errors and defects in construction which then lead to maintenance issues and asset management. The factors of accessibility, materials, design and documentation standardization have been discussed thoroughly for better understanding in improving maintenance and physical asset management in project commissioning

Development of Conceptual Vehicle All-Wheel-Nuts Remover

As the standard of living in Malaysia has increased, most of the families have at least one vehicle, typically, car, to move easily and quickly. With the increment of the number of cars in the road, the number of cars’ problem due to tyre failure has increased. Often, the car is provided with tyre wheel nuts remover and jack for instance spare tyre replacement. Nevertheless, due to the difficulty in applying the required torque to remove the nuts, most of the time, driver rely on the tow truck and available nearest mechanic to solve the problem. This always happen to the elderly or female drivers. Based on the capability of torque application by these drivers, a vehicle all-wheel-nuts remover is designed. The remover is designed to be ergonomic to be used, easy maintenance, easy storage, easy to handle and able to remove all nuts at once. The design of the remover is based on standard pitch circle diameter (PCD) of 100 mm and 4 numbers of nuts for most of the cars available

ASSESSMENT OF THE ACOUSTICAL PERFORMANCE IN MALACCA MOSQUE,MALAYSIA: A CASE STUDY ON THE SAYYIDINA ABU BAKAR MOSQUE

As a building for worship and one of the important symbols in Islam, a mosque is usually designed with its architectural grandeur. Among of the characteristics is its spacious interior to create a perception so that people will feel ’small’ when entering the house of God. Most mosques therefore have high ceiling and are usually constructed with dome shape. In Malacca, Malaysia however, the architectural of the mosque resembles the traditional Malay house where the ceiling follows a pyramidal shape. This paper discusses the acoustical condition of the mosque in Malacca. The Sayyidina Abu Bakar Mosque is presented here for a case study. Measurement of its reverberation time was conducted and the results are validated with simulation data from CATT room acoustics software. Other important acoustical parameters are evaluated such as the early decay time, clarity, definition, lateral fraction and speech transmission index