دانلود رایگان مقاله لاتین رادوم آنتن هواپیما از سایت الزویر
عنوان فارسی مقاله:
ارزیابی غیر مخرب رادوم آنتن هواپیما UHF بر اساس تصویربرداری انتشار اولتراسونیک پالس اکو
عنوان انگلیسی مقاله:
In situ non-destructive evaluation of an aircraft UHF antenna radome based on pulse-echo ultrasonic propagation imaging
سال انتشار : 2016
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مقدمه انگلیسی مقاله:
1. Introduction
Composite materials have been extensively used in aerospace and many other industries. Due to limitations of manufacture and maintenance, bolted joints are quite commonly used in composite structures [1]. However, the drilling of holes cuts the fiber and causes local stress concentration, resulting in reduction of load carrying capacity. To ensure safety and increase weight saving effi- ciency, the joint structures must be designed seriously, and their mechanical behavior should be studied carefully [2–5]. The failure mode and strength are important properties for composite bolted joints. The main failure modes of multi-bolt joints include net-section failure, bearing failure and shear out failure as shown in Fig. 1. The bearing failure is a progressive process, while net-section failure and shear out failure occur immediately and catastrophically. The latter two failure modes may reduce the load carrying capacity or cause instant failure of the whole structure. That is the reason why bearing failure mode is preferred in joint structural design and the other two modes should be avoided. By adjusting ±45 layer ratio and the end distance of connected objects, shear out failure can be suppressed and the main failure modes are the other two failure modes. The control of failure modes is very important for bolted joint structure design, thus failure mode prediction methods of multi-bolt composite joints are needed to be investigated. Many researchers have investigated mechanical properties of single-bolt composite joints [6–8]. Compared with single-bolt joints, there are various load transferring paths in multi-bolt structures, causing more complicated structural characters. Current mechanical investigations on multi-bolt joints mainly focus on bolt load distribution [9–14] and predictions of failure modes and strength. The failure envelope method is a common accepted engineering method for failure mode and failure load prediction. The failure envelope method is originally proposed by HartSmith [15] to predict tensile and bearing failure of double-lap multi-bolt joints with quasi-isotropic or near-quasi isotropic layups. He found that a linear interaction exists between the bearing stress along the bolt hole and the remaining tension stress running by that hole to be reacted elsewhere (bypass stress). Based on the experimental results, he proposed the bearing-bypass failure envelope. Then, Crews and Naik [16], Rao et al. [17], Camanho et al. [18,19], Bois et al. [20] applied and developed the method. In the failure envelope, the line corresponding to bearing failure is a contour line determined by single-bolt bearing strength. But Liu et al.
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کلمات کلیدی:
In situ Non-Destructive Evaluation of an Aircraft UHF ... - ResearchGate https://www.researchgate.net/.../309279414_In_situ_Non-Destructive_Evaluation_of_an... In situ Non-Destructive Evaluation of an Aircraft UHF Antenna Radome based on Pulse-Echo Ultrasonic Propagation Imaging on ResearchGate, the ... In situ non-destructive evaluation of an aircraft UHF ... - DeepDyve https://www.deepdyve.com/.../in-situ-non-destructive-evaluation-of-an-aircraft-uhf-an... Read "In situ non-destructive evaluation of an aircraft UHF antenna radome based on pulse-echo ultrasonic propagation imaging, Composite Structures" on ... Sparrho | In situ Non-Destructive Evaluation of an Aircraft UHF Anten https://www.sparrho.com/...non-destructive-evaluation-of-an-aircraft-uhf.../9d52cd/ Oct 18, 2016 - Most aircraft antennas are protected by radomes made of composite materials. However, antenna radome structures are easily damaged by ... Defect visualization of aircraft UHF antenna radome using full-field ... iopscience.iop.org/article/10.1088/1757-899X/152/1/012027/meta by HJ Shin - 2016 - Related articles Defect visualization of aircraft UHF antenna radome using full-field pulse-echo ... effective non-destructive inspection technique for the composite radome structures. ... Handbook - Airframe (Oklahoma City: Airman Testing Standards Branch). In situ non-destructive evaluation of an aircraft UHF antenna radome ... koasas.kaist.ac.kr/handle/10203/220392 by HJ Shin - 2017 - Related articles Most aircraft antennas are protected by radomes made of composite materials. However, antenna radome structures are easily damaged by external forces and ... Nondestructive evaluation of multilayer capacitors using ... - IEEE Xplore ieeexplore.ieee.org/document/300659/ by HT Sun - Cited by 2 - Related articles Electromechanical resonances of ceramic multilayer capacitors are calculated mechanically free and clamped boundary conditions using vibration and ...
