نتایج جستجو برای: Acoustic emission

تعداد نتایج: 261222  

Journal: :جنگل و فرآورده های چوب 0
حوری شریف نیا دانشگاه تربیت مدرس سعید کاظمی نجفی گروه علوم و صنایع چوب و کاغذ، دانشکده منابع طبیعی ، دانشگاه تربیت مدرس مهدی احمدی نجف آبادی دانشگاه صنعتی امیر کبیر

with the aim of identifying failure mechanism in oriented strand boards, failure behavior of wood strands under tensile load was investigated using acoustic emission technique. resinated and unresinated strands were arranged at top, middle and bottom section of the board before pressing. tensile and acoustic emission tests were performed simultaneously on treated and control samples. using tens...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه صنعتی امیرکبیر(پلی تکنیک تهران) - دانشکده مهندسی مکانیک 1386

قابلیت استفاده از روش آکوستیک امیشن برای پایش فرآیندهای اصطکاکی به عنوان روشی تکمیلی در کنار سایر روشها مانند نیروسنجی توسط محققان متعددی مورد تأیید قرار گرفته است. در این پروژه به بررسی دقیق تر پدیده های اصطکاکی به کمک آکوستیک امیشن پرداخته می شود. شرایط تولید سیگنال های آکوستیک امیشن در شکل دهی ورق های فلزی از جمله مواردی است که مورد بررسی قرار گرفته است. برای انجام آزمایشات، سه مجموعه آزمایش...

Journal: :journal of mechanical research and application 2012
e hodaei m javadi a broumandnia h sadeghi

this paper deals with an inspection of defects including corrosion and leakage by acoustic emission (ae) in an oil tank floor. in contrast to intrusive methods such as magnetic flux leakage, eddy current or ultrasonic, there is no need to emptying and entering the tank in ae method in order to inspection. in this research ae investigation and ae source location is presented in detail. the resul...

In this study, the longitudinal and hoop tensile strengths of an industrial ±55° Glass Reinforced Epoxy (GRE) pipe with eighteen layers as well as the associated failure mechanisms are determined. To obtain the longitudinal and hoop tensile strengths values, three specimens are cut from the studied GRE pipe in each direction. A comparison is done between both the strength values, and the fractu...

Journal: :Springer aerospace technology 2021

Abstract Acoustic emission (AE) is one of the most promising methods for structural health monitoring (SHM) materials and structures. Because its passive non-invasive nature, it can be used during operation a structure supply information that cannot collected in real time through other techniques. It based on recording study elastic waves are excited by irreversible processes, such as crack nuc...

In this study, the change at rubbing surfaces has been investigated experimentally using an acoustic emission signal monitoring system. A steel ring is slipped on the surface of  a metallic sheet to simulate frictional conditions. The mechanical disturbances caused by the movement of the ring produce stress waves propagating along the sheet surface. The out of plane displacement of the sheet su...

Composites have been widely used in the aerospace industry. Due to the requirement of a high safety for such structures, they could be considered for health monitoring. The acoustic emission approach is one of most effective methods for identifying damages in composites. In this article, standard specimens were made from carbon fibers and the epoxy resin, with the [03/902/...

Journal: :iranian journal of otorhinolaryngology 0
ahmadshah farhat neonatal research center, imam reza hospital, faculty of medicine, mashhad university of medical sciences, mashhad, iran. mohammad mahdi ghasemi sinus and surgical endoscopic research center, faculty of medicine, mashhad university of medical sciences, mashhad, iran. javad akhondian 3department of pediatrics, ghaem hospital, mashhad university of medical sciences, mashhad, iran. ashraf mohamadzadeh neonatal research center, imam reza hospital, faculty of medicine, mashhad university of medical sciences, mashhad, iran. habibollah esmaeili neonatal research center, imam reza hospital, faculty of medicine, mashhad university of medical sciences, mashhad, iran. rana amiri neonatal research center, imam reza hospital, faculty of medicine, mashhad university of medical sciences, mashhad, iran.

introduction: according to world health organization (who) 2001 statistics, hearing disorders are the most common congenital disease, and the incidence rate among high-risk newborns is as much as ten times as high as that in healthy neonates. however, 78% of screening test failures are well-baby nursery babies. the joint committee on infants’ hearing (jcih) has emphasized the importance of earl...

2018
Peng Wei Xiaole Han Dong Xia Taolin Liu Hao Lang

Acoustic emission technology has been applied to many fields for many years. However, the conventional piezoelectric acoustic emission sensors cannot be used in extreme environments, such as those with heavy electromagnetic interference, high pressure, or strong corrosion. In this paper, a novel fiber-optic ring acoustic emission sensor is proposed. The sensor exhibits high sensitivity, anti-el...

Carbon / epoxy composite is one of the most useful polymer matrix composites that has special properties such as high strength-to-weight ratio, high hardness, high corrosion resistance, Resistance to nuclear radiation has high consumption in different industries such as aerospace industry. Therefor monitoring of loading of this type of composite is important. In order to determine failure mecha...

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