دانلود مقاله بررسی رفتار پیچشی لرزه ای دیوارهای بتن مسلح
چکیده
مقدمه
مطالعه تجربی
نتایج آزمون و بحث
نتیجه گیری
منابع
Abstract
Introduction
Experimental Study
Test Results and Discussion
Conclusions
References
چکیده
در این مقاله رفتار پیچشی لرزه ای دیوارهای بتن مسلح به صورت تجربی مورد بررسی قرار گرفته است. دیوارهای بتن آرمه با نسبت‌های 7، 6 و 5 در مقیاس 1/2 تولید شده‌اند. از هر نسبت ابعاد سه نمونه تولید شده است. علاوه بر این نمونه ها، یک نمونه مرجع با نسبت ابعاد 6 تولید شده است. برای تعیین پروتکل بارگذاری از آزمون نمونه مرجع استفاده شده است. سعی شده است با تغییر افزایش بار در آزمایش نمونه مرجع، افزایش بار بهینه تعیین شود. بدین ترتیب ده آزمایش پیچش لرزه ای با استفاده از این نمونه ها انجام شده است. هدف اصلی از آزمایش‌ها، بررسی تجربی رفتار پیچشی لرزه‌ای خالص دیوارهای بتن مسلح تحت بار محوری است. علاوه بر این، هدف بررسی اثرات نسبت ابعاد بر رفتار پیچشی با استفاده از آزمون‌ها بوده است. در نتیجه مطالعه؛ ترک خوردگی و حداکثر گشتاورهای پیچشی، منحنی های زاویه گشتاور-پیچش، سختی های پیچشی، مصرف انرژی، الگوهای آسیب دیوارهای بتن مسلح به دست آمده است. از نتایج مشاهده می شود که دیوارهای بتنی مسلح با مقاطع بزرگ از مقاومت پیچشی و سختی پیچشی بیشتری برخوردارند. با افزایش نسبت ابعاد از 5 به 7، میانگین ترک خوردگی و حداکثر گشتاورهای پیچشی 65.7 درصد و 45.5 درصد افزایش یافته است. متوسط نسبت سختی پیچشی پس از ترک به سختی پیچشی قبل از ترک به ترتیب 0.0781، 0.0922 و 0.0843 برای دیوارهای با نسبت ابعاد 5، 6 و 7 محاسبه شده است. به این نتیجه رسیدیم که انتخاب نسبت ابعاد 5 یا 6 از نظر رفتار پیچشی مناسب است.
توجه! این متن ترجمه ماشینی بوده و توسط مترجمین ای ترجمه، ترجمه نشده است.
Abstract
In this paper, the seismic torsional behavior of reinforced concrete walls has been studied experimentally. Reinforced concrete walls having 7, 6, and 5 aspect ratios have been produced on a 1/2 scale. Three specimens have been produced from each aspect ratio. In addition to these specimens, a reference specimen having a 6 aspect ratio has been produced. The reference specimen test has been used for determining the loading protocol. It has been tried to determine optimum load increase by changing load increments in the reference specimen test. Thus, ten seismic torsion tests have been carried out by using these specimens. The main purpose of the tests is to experimentally investigate the pure seismic torsional behavior of reinforced concrete walls which are under axial load. Moreover, it has been aimed to investigate the effects of the aspect ratio on torsional behavior using the tests. As a result of the study; cracking and maximum torsional moments, torque-twist angle curves, torsional stiffnesses, energy consumptions, damage patterns of the reinforced concrete walls have been obtained. It is observed from the results that the reinforced concrete walls having large cross-sections have greater torsional strengths and torsional stiffnesses. The average cracking and maximum torsional moments have increased 65.7% and 45.5% as the aspect ratio increased from 5 to 7.
Introduction
Countries that are especially located in earthquake zones aim to minimize earthquake effects by publishing various earthquake standards. When these earthquake standards are examined, it is seen that structural irregularities are considered a very important factor in earthquake-resistant building design. For this reason, many measures are taken to prevent these structural irregularities. As can be understood from this situation, if structural irregularities cannot be prevented in buildings, the buildings are inevitably damaged under earthquake effects. One of the most important structural irregularities is torsional irregularity. When mass center and rigidity center do not coincide in buildings, torsional irregularity can occur. Irregular geometry and stiffness distribution in the plan are the most important causes of torsional irregularity in buildings. If the structural elements are placed irregularly or asymmetrically in the plan, undesirable torsional effects have occurred in the buildings. Reinforced concrete walls which are not placed regularly or symmetrically are caused torsional irregularities in buildings.
Results and analyses
This study aims to experimentally investigate the pure seismic torsional behavior of reinforced concrete walls which have different aspect ratios. Pure torsional effects have been created by applying reversed cyclic lateral loads to reinforced concrete walls which are under axial loads. Ten specimens have been produced and ten torsion tests have been performed in experimental studies. Torque-twist angle relation, torsional strength and stiffness, energy consumption, and damage pattern of the specimens have been obtained and evaluated in detail. After comparing the test results with both each other and the studies in the literature, it is clearly seen that compatible results have been obtained in terms of the pure torsional behavior of reinforced concrete elements. In other words, when the results of this study are investigated in general, all test results show that pure torsional behavior has occurred in reinforced concrete walls.