دانلود مقاله تاثیر شبکه فلزی و بتن مسلح بر مقاومت ضربه ای
چکیده
مقدمه
برنامه آزمایشی
نتایج و بحث
نتیجه گیری
منابع
Abstract
Introduction
Experimental program
Results and discussion
onclusions
References
چکیده
در جامعه مدرن، تاکید روزافزون بر طراحی ایمنی سازه است که نه تنها بار خارجی را در نظر می گیرد، بلکه تا کاهش تداخل الکترومغناطیسی گسترش می یابد. به طور کلی، مطالعات تنها اثر حفاظتی روش یا مواد مقاوم‌سازی را در نظر می‌گیرند و مطالعات کمی رابطه بین مناطق آسیب‌دیده و اثربخشی محافظ را در نظر گرفته‌اند. بنابراین، تأثیر پارامترهای شبکه فلزی و بتن مسلح با الیاف (HSDC) بر اثربخشی محافظ با و بدون بار ضربه ای در این تحقیق مورد بررسی قرار می گیرد. مقاوم سازی دیوارهای بتنی با چهار نوع شبکه فلزی و سه نوع ضخامت HSDC در نظر گرفته شد. علاوه بر این، رابطه بین نسبت ناحیه آسیب‌دیده و اثربخشی محافظ با استفاده از تست ضربه با وزن کم سرعت مورد ارزیابی قرار گرفت. در نمونه‌های با شبکه فلزی یا HSDC، اثر محافظتی با لایه تقویتی (13.4-64.1٪) یا ضخامت (35.6-46.2٪) افزایش و اندازه شبکه (> 7.8٪) کاهش یافت. نمونه تقویت شده با کمتر از 55.1٪ و 101٪ نسبت فضای آزاد تک لایه و دو لایه، به ترتیب، بیش از 40 دسی بل اثر محافظتی را نشان می دهد. برای نمونه تقویت شده با HSDC، اثر محافظتی با ناحیه تقویت افزایش یافت، به جز کمتر از 6٪. کوچک‌ترین شبکه فلزی و ضخیم‌ترین نمونه تقویت‌کننده HSDC مقاومت ضربه‌ای بهبود یافته و اثر محافظتی عالی پس از بارگذاری ضربه نشان دادند.
توجه! این متن ترجمه ماشینی بوده و توسط مترجمین ای ترجمه، ترجمه نشده است.
Abstract
In modern society, an ever-increasing emphasis is placed on structural safety design that not only considers external loading but extends to reduced electromagnetic interference. Generally, studies only consider shielding effectiveness of strengthening method or materials, and few studies have considered the relationship between damaged areas and shielding effectiveness. Therefore, the influence of metallic grid parameters and fiber reinforced concrete (HSDC) on shielding effectiveness with and without impact loading are studied in this research. Concrete wall strengthening with four types of metallic grid and three thickness types of HSDC were considered. Moreover, the relationship between damaged area ratio and shielding effectiveness was evaluated utilizing the low-velocity drop-weight impact test. In specimens with metallic grid or HSDC, shielding effectiveness with strengthening layer (13.4–64.1%) or thickness (35.6–46.2%) increase and grid size (> 7.8%) decreased. Specimen strengthened by smaller than 55.1% and 101% of the free space area ratio of single and double layer, respectively, exhibit more than 40 dB shielding effectiveness.
Introduction
With the sustained development of the national economy many high-rise, commercial and civil buildings have emerged, as well as the increasing need for electrical power. People are also more and more concerned about the surrounding electromagnetic environment with the improving living conditions. Electromagnetic interference (EMI) pollution has been recognized as a worrying danger for commercial apparatus, biological systems (human health), high-quality information and defense safe technology. Therefore, this pollution has become an extremely serious universal problem, and it has renewed focus to carry out extensive research into EMI shielding materials and methods. The EMI shielding materials and methods are primarily focused on the refection and /or absorption of EMI radiation to prevent the radiation penetration passing through the shielding materials and methods. In general, conductive materials (such as metals, carbon materials, magnetic materials) are extensively used for EMI shielding according to their high refectivity.
Results and analyses
This study evaluated the SE of concrete walls strengthened by metallic grids and high strength high ductility concrete. A variety of strengthening methods were used to evaluate the SE and impact resistance. From this investigation, the following conclusions can be drawn: 1) The specimen strengthened with metallic grids displayed an increase in SE with a decrease in grid size, which were 0.2–7.9, 1.4–20.9, 4.0–22.7, and 8.2–31.3 dB, respectively, higher than specimens without a metallic grid. Moreover, the specimens reinforced by diferent types of metallic grids were improved to a certain extent in SE, with smaller grid sizes producing more efective SE responses irrespective of single- or double-layer rein - forcement.