نوع مقاله : مقاله پژوهشی
نویسندگان
1 دانشجوی کارشناسی ارشد، مهندسی مکانیک، دانشگاه تربیت مدرس، تهران
2 استاد، مهندسی مکانیک، دانشگاه تربیت مدرس، تهرا ن
3 دانشجوی دکترا، مهندسی مکانیک، دانشگاه تربیت مدرس، تهرا ن
چکیده
ازجمله پراهمیتترین تحلیلهایی که در زمان طراحی سازههای کامپوزیتی صورت میگیرد، تحلیل پایداری آنها تحت بارمحوری یا تحلیل رفتار کمانشی است. روش همبستگی ارتعاشی از دقیقترین روشهای تعیین بار کمانش سازه به صورت غیرمخرب است. روش همبستگی ارتعاشی یک روش غیرمخرب مبتنی بر تحلیل مودال است که با اندازهگیری فرکانسهای طبیعی سازه تحت بارهای مختلف محوری به پیشبینی بار کمانش سازه میپردازد. یکی از متداولترین آسیبهایی که در زمان ساخت و یا در زمان سرویس ممکن است به سراغ کامپوزیتها بیاید، لایهلایه شدگی این مواد بوده، که با عنوان تورّق مطرح میگردد. بنابراین بررسی کمانش سازههای مرکب دارای آسیب تورّق از اهمیت بالایی برخوردار است که در این مطالعه سعی شده است که به بررسی تجربی این پدیده به کمک روش غیر مخرب همبستگی ارتعاشی و مقایسه آن با نتایج آزمون مخرب کمانش، بهصورت تجربی، پرداخته شود. در واقع، این مقاله قابلیت اعمال روش همبستگی ارتعاشی بر سازههای دارای آسیب را بررسی میکند. برای رسیدن به این هدف ورقهای کامپوزیتی مستطلیی دارای تورق سرتاسری در عرض به کمک روش تزریق رزین به قالب به کمک خلا ساخته شد. هریک از نمونهها تحت آزمون کمانش مخرب قرار گرفت. سپس به منظور بررسی کارایی روش همبستگی ارتعاشی، آزمون مودال تجربی به منظور تعیین فرکانس طبیعی سازه در بارهای فشاری مختلف انجام گرفت. نتایج نشانگر آن اند که روش همبستگی ارتعاشی دقت بسیار خوبی در تعیین بار کمانش ورق کامپوزیتی دارای تورق داشته و درصد اختلاف کمتر از 8 درصد میان نتایج آزمون مخرب و روش غیرمخرب همبستگی ارتعاشی دال این موضوع است
کلیدواژهها
موضوعات
عنوان مقاله [English]
Experimental Prediction of Buckling Load of Rectangular composite Plate with through-the-width Delamination using Nondestructive Vibration Correlation Technique
نویسندگان [English]
- Pouria Pouria Azami-Googarchin 1
- Gholam-hossein Rahimi 2
- Mohammad Sajad Gazor 3
1 Department of Mechanical Engineering, Tarbiat Modares University, Tehran, Iran
2 Department of Mechanical Engineering, Tarbiat Modares University, Tehran, Iran
3 Department of Mechanical Engineering, Tarbiat Modares University, Tehran, Iran
چکیده [English]
One of the most important analysis during designing composite structures is its stability under compressive loads or buckling behavior analysis. Vibration correlation technique is one of the most accurate method to determine buckling load of structures non-destructively. The vibration correlation technique is a non-destructive method based on a modal analysis which predicts the buckling load of the structure by means of measuring the natural frequencies under different loads. One of the most common damages occurring to composites during manufacturing or in-service is debonding between layers known as delamination. Consequently, investigation of buckling of delaminated structures is in a great importance and in this study has tried to cover this issue experimentally using non-destructive vibration correlation technique and comparing its results with common destructive buckling tests. In fact, this paper investigates applicability of applying VCT on damaged structures. In order to reach to this goal, rectangular composite plates with through-the-width delamination using VARTM process has been fabricated. The buckling load of each specimen was determined using common destructive buckling test. Consequently, In order to measure the natural frequencies at different loadings, experimental modal analysis was conducted. The results show that the vibration correlation technique has a very good accuracy in determining the buckling load of the delaminated composite plate and the difference percentage between destructive tests results and the non-destructive vibration correlation technique results which is less than 8% approves it.
کلیدواژهها [English]
- Buckling
- Vibration correlation technique
- Composite plate
- Delamination
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