تحليل ضربه‌ كم‌سرعت خارج از مركز ورق ساندويچي با تكيه‌گاه هاي نقطه‌اي به شيوه نيمه تحليلي

Semi-Analytical Eccentric Low-Velocity Impact Analysis of Sandwich Plates Resting on Point Supports, Using a Semi-Analytical Method

در پژوهش كنوني، رفتار ورق ساندويچي با تكيه‌گاه هاي نقطه‌اي در معرض ضربه‌ كم‌سرعت خارج از مركز، براي اولين بار بررسي شده است. نوآوري ديگر، شامل پيشنهاد يك حل نيمه تحليلي به همراه فرمولبندي انرژي جديد، جهت در نظر گرفتن وابستگي مكاني و استفاده از يك روش انتگرال گيري عددي زماني ضمني مي باشد. معادلات حركت برپايه اكسترمم سازي انرژي پتانسيل كل، با در نظر گرفتن كار نيروهاي اينرسي، به شيوه ريتز پيدا شده و به طور ابتكاري، به فرم شبه استاتيكي تبديل شده است. بر خلاف پژوهشهاي موجود، اثر سفتي لايه هاي زيرين بر ضربه نيز دخالت داده شده است.

In the present research, behavior of a sandwich plate with point supports subjected to an eccentric low-velocity impact is investigated. In this regard, time histories of the contact force and lateral deflection of a sandwich plate with simply supported edges are compared with those of a plate resting on point supports. This comparison has not been accomplished so far, even for the single-layer isotropic plates. Other novelty consists of proposing a semi-analytical solution in conjunction with a new energy formulation to consider the spatial dependency and using a numerical time integration method, implicitly. The governing equations of motions are found based on extremizing the total potential energy, including work of the inertia forces, employing Ritz technique and reduced to quasi-static one through a novel approach. In contrast to the available researches, influence of the lower layer on the stiffness of the contact region is incorporated. Verification of the results has been accomplished based on results of ABAQUS computer code. In the results section, the significant effects of the point supports (in comparison to the complete edge support), initial velocity of the indenter, and the aspect ratio of the plate on time histories of the contact force and lateral deflection of the plate are investigated