Reinforced concrete pipe (RCP) has been one of the most common pipes for medium to large diameter utility systems including sanitary sewer, and storm drainage systems. RCP typically has superior structural properties combining high compressive strength from concrete and tensile strength from reinforced steel. RCP tends to deteriorate over time due to hydrogen sulfide (H2S) gas in sewage and man...

The effect of local drop of wall stiffness in pressurized waterways on the pressure wave speed and the wave attenuation during transients is investigated experimentally. A new signal-processing procedure to identify the presence of a weak reach is introduced and validated by physical experimentation based on assessing the pressure and vibration records acquired at both ends of a multi-reach ste...

Active control of low frequency pump noise in water-filled pipes is being developed at AMRL for acoustic signature control on maritime platforms. The present approach is based on separate fluid and wall-axial wave control with collocated control sources. One of the main problems encountered in the design of suitable control sources is their operating effectiveness over a large range of internal...

The failure of steel liner of pressure shafts of hydropower plants can have catastrophic consequences. The partial or total loss of the liner support’s rigidity is characterized by a local change of the hydro-acoustic properties and creates reflection boundaries for the water waves. This paper presents a new monitoring method for detecting and locating weak reaches by processing reflected water...

We developed a novel fiber-optic acoustic emission (AE) monitoring system and applied this to gas-leak detection. The system is a Mach-Zehnder, homodyne-type optical fiber laser interferometer with a phase compensation feedback circuit. The phase compensation was given by a piezo-actuator, which can maintain the system at being quadurature condition. The system was demonstrated to measure the i...

Buried steel fuel pipelines are critical lifelines for the society and the economy but are very vulnerable to earthquake-induced ground failure. Traversing seismic areas inevitably results in several pipe-fault crossings. Fault rupture forces a buried pipeline to undergo deformations that could be substantial and heavily endanger its integrity. Due to the grave consequences of a potential pipe ...

ommunication from within the steel pipeline by inspecting or sensing tools or robots is usually performed via a cable. As the length of the tether restricts the communication distance and as the cable may encumber the tool’s movement, we explore the feasibility of acoustic communication from within the liquid-filled pipe to an external sink through the steel pipe walls. The paper derives the so...

Z. Burzić, Military Technical Institute, Belgrade, Serbia. Dž. Gačo, F. Islamović, E. Bajramović, Technical faculty, University of Bihac,Bihac, Bosnia and Herzegovina. M. Burzić, University of Belgrade, I.C. Faculty of Mechanical Engineering, Belgrade, Serbia. In present paper, experimental investigations have included the eff ect of exploitation conditions (exploitation time and temperature) o...

The phenomenon of ratchetting is defined as constant accumulation of plastic strain or deformation under combined steady state and cyclic loading. It can reduce the fatigue life or can cause failure of piping components or systems subjected to seismic or other cyclic loads. The uniaxial ratchetting characteristics of SA333 Gr.6 steel have been investigated at room temperature in the present pap...