تحلیل عددی تاثیر هندسه سلول‌های هسته بر رفتار مکانیکی کامپوزیت‌های ساندویچی

از میان طیف گسترده‌ی مصالح نوین، کامپوزیت‌های مشبک در طراحی سازه‌های تحت بار، جایگزین بسیار مناسبی برای مصالح معمولی در صنایع مختلف می‌باشند. در بخش اول این مطالعه، سه چیدمان مختلف برای هسته‌های یک تیر ساندویچی در نظر گرفته شده و تاثیر شکل سلول‌ها بر رفتار مکانیکی سازه بصورت عددی بررسی شده است. ابتدا وضعیت ارتعاشی هر تیر به کمک تحلیل مودال بررسی شده و در بخش دوم با تغییر ضخامت هسته پانل‌های ساندویچی مشبک با شبکه‌های شش‌ضلعی مشابه، به بررسی عددی تاثیر ضخامت هسته بر رفتار مکانیکی کامپوزیت‌ پرداخته‌ شده است. نتایج حاکی از آن است که فرکانس طبیعی، خیز و نسبت استحکام به وزن پانل‌ها به ترتیب نزولی به چیدمان‌های مربعی، شش‌ضلعی و مثلثی تعلق داشته است. خیز و تنش معادل نتایجی بودند که از شبیه‌سازی عددی هر مدل به دست آمدند. با افزایش ضخامت هسته، نسبت استحکام به وزن به صورت چشمگیر افزایش می‌یابد، بطوریکه با افزایش هرچه بیشتر ارتفاع هسته، خیز تیر کاهش و آستانه‌ی قدرت تحمل بار و استحکام افزایش می‌یابد. در حالتی که ضخامت هسته لانه‌زنبوری برابر با ضخامت پوسته است، تنها با %25 افزایش حجم مصالح می‌توان سختی خمشی را نسبت به ورق صلب را تا 7.12 برابر رساند. مقایسه و اعتبارسنجی داده‌های به دست آمده از تحلیل عددی با نتایج آزمایشگاهی موجود نشان می‌دهد که تنها با 4 درصد اختلاف، همخوانی بسیار نزدیکی بین نتایج وجود دارد.

numerical analysis of core cell geometry effect on the mechanical behavior of sandwich composites

abstract among the myriad new industrial materials designed for under-load structures, honeycomb composites are emerging as superior substitutes for conventional materials across various industries. this study explores the mechanical behavior of sandwich beams with three distinct core cell configurations: rectangular, honeycomb, and triangular. modal analysis was utilized to investigate the vibration characteristics, and subsequent studies assessed the impact of core thickness on mechanical performance. results reveal that, in terms of natural frequencies, deflections, and the strength-to-weight ratio, the configurations rank as rectangular, honeycomb, and triangular in descending order. increasing core thickness reduces beam deflection and enhanced load-bearing capacity, despite increased weight. a comparison between isotropic plates and honeycomb composites demonstrates that bending stiffness can be improved by up to seven times with just a 25% increase in volume. the numerical findings are validated against empirical data, showing a close agreement with only a 4% discrepancy.  introduction the development of advanced materials for structural applications is crucial for improving performance and efficiency in various industries. honeycomb composites, characterized by their lightweight and high-strength properties, have shown considerable promise as replacements for traditional materials. this study investigates the effects of different core cell configurations and core thicknesses on the mechanical properties of honeycomb sandwich beams. the goal is to enhance understanding of how these factors influence vibration characteristics, deflection, and strength-to-weight ratios, thereby providing insights into optimizing honeycomb composites for structural applications.  materials and methods three core cell configurations were selected for this study: rectangular, honeycomb, and triangular. each configuration was used as the core of a sandwich beam, and their mechanical behaviors were evaluated using numerical simulations. modal analysis was performed to study the vibration characteristics of the beams. in addition, the core height was varied to examine its effect on the mechanical properties, includingnatural frequencies, deflection, and strength-to-weight ratio. the simulations were conducted using ansys software, and the results were compared with empirical data to validate the numerical findings.  results the numerical analysis indicated that the natural frequencies, deflections, and strength-to-weight ratios of the beams varied significantly with core cell configuration. the rectangular configuration exhibited the highest natural frequencies, while the triangular configuration had the lowest. deflection and von-mises stress analysis revealed that increasing the core thickness generally reduced beam deflection and improved the load-bearing capacity. notably, when comparing honeycomb composites to isotropic plates, the former demonstrated up to seven times greater bending stiffness with only a 25% increase in volume. the validation of numerical results against empirical data showed a high degree of accuracy, with only a 4% difference.  discussion and conclusion this study confirms that honeycomb composites are highly effective in improving the mechanical performance of sandwich beams. the choice of core cell configuration significantly influences the natural frequencies, deflections, and strength-to-weight ratios. increasing core thickness enhances structural performance, though at the cost of increased weight. the findings also highlight the substantial benefits of honeycomb composites over isotropic plates in terms of bending stiffness. the close agreement between numerical and empirical results underscores the reliability of the numerical simulations used in this study. future work may explore additional core configurations and material properties to further optimize honeycomb composites for various structural applications.