Mehrdad Shokrieh, M., Akbari, S. (2011). Investigation of Important Parameters in Residual Stress Determination in Isotropic Plates and Laminated Composites by Slitting Method. Journal of Simulation and Analysis of Novel Technologies in Mechanical Engineering, 4(1), 35-45.
Mahmood Mehrdad Shokrieh; Saeid Akbari. "Investigation of Important Parameters in Residual Stress Determination in Isotropic Plates and Laminated Composites by Slitting Method". Journal of Simulation and Analysis of Novel Technologies in Mechanical Engineering, 4, 1, 2011, 35-45.
Mehrdad Shokrieh, M., Akbari, S. (2011). 'Investigation of Important Parameters in Residual Stress Determination in Isotropic Plates and Laminated Composites by Slitting Method', Journal of Simulation and Analysis of Novel Technologies in Mechanical Engineering, 4(1), pp. 35-45.
Mehrdad Shokrieh, M., Akbari, S. Investigation of Important Parameters in Residual Stress Determination in Isotropic Plates and Laminated Composites by Slitting Method. Journal of Simulation and Analysis of Novel Technologies in Mechanical Engineering, 2011; 4(1): 35-45.
Investigation of Important Parameters in Residual Stress Determination in Isotropic Plates and Laminated Composites by Slitting Method
1Professor, Iran University of Science and Technology
2M. Sc. Student, Iran University of Science and Technology.
Abstract
In the slitting method, a small width slit is created incrementally through the thickness of the stressed specimen and the released strains in each increment are recorded by a strain gauge. Compliance coefficients relate the measured strains to the residual stresses. This paper investigates the important parameters influencing the calculation of compliance coefficients for isotropic plates and laminated composites by finite element analysis. First, the process of slitting in isotropic materials is simulated using two and three-dimensional finite element models. The results show complete agreement between these two models. Calculation of average strain at the strain gauge location is necessary for the calculation of compliance coefficients. For this purpose, strain-based and displacement-based methods are used. In addition, the effect of slit width on compliance coefficients is checked. Then, released strains by strain gauges with different gauge-lengths are compared with each other. The results show that the strain gauges with smaller gauge-lengths can record higher values of released strain and consequently increase the precision of measurements. Lastly, compliance coefficients for two glass/epoxy and carbon/epoxy laminates are calculated using the proposed three-dimensional model.
بررسی پارامترهای مؤثر در تعیین تنش های پسماند در صفحات فلزی و چندلایه‌های کامپوزیتی با روش شیارزنی
Authors [Persian]
محمود مهرداد شکریه, سعید اکبری رکن‌آبادی
Abstract [Persian]
روش شیارزنی یکی از روشهای پرکاربرد در اندازهگیری تنشهای پسماند است که طی آن شیاری در چند مرحله در قطعه مورد نظر ایجاد شده و کرنشهای آزاد شده در هر مرحله به وسیله کرنشسنج ثبت میشود. ارتباط بین کرنشهای ثبت شده و تنشهای پسماند به وسیله ماتریس ضرایب نرمی صورت میگیرد. در این تحقیق به کمک روش اجزای محدود، پارامترهای مؤثر در محاسبه مقادیر ضرایب نرمی برای صفحات فلزی ایزوتروپیک و همچنین چند لایههای کامپوزیتی بررسی شده است. در ابتدا فرایند شبیه‌سازی برای صفحات ایزوتروپیک به‌صورت دو و سه بعدی انجام گرفته است. نتایج به‌دست آمده بیانگر تطابق کامل نتایج دو مدل است. برای محاسبه ضرایب نرمی نیاز به محاسبه کرنش متوسط در محل کرنشسنج است. برای این کار از روشهای مبتنی بر کرنش و مبتنی بر جابه‌جایی استفاده شده است. همچنین با مقایسه ترک و شیار، تأثیر عرض شیار بر ضرایب نرمی بررسی شده است. سپس میزان کرنش ثبت شده توسط کرنشسنجهای با طول اندازه‌گیرهای مختلف مقایسه و مشخص شد با استفاده از کرنشسنجهای با طول اندازه‌گیر کمتر، میزان کرنش ثبت شده افزایش یافته و در نتیجه خطای اندازهگیری کاهش می‌یابد. در نهایت با استفاده از مدل سهبعدی ارائه شده ضرایب نرمی برای دو چندلایهای کامپوزیتی کربن- اپوکسی و شیشه- اپوکسی تعیین شدهاند.
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