تحليل كمانش ورق كامپوزيتي با سوراخ هاي دايره اي روي تكيه گاه الاستيك در شرايط مرزي و بارگذاري هاي لبه اي پاره اي مختلف، به شيوه نيمه تحليلي

Semi-Analytical Buckling Analysis of a Composite Plate with Circular Cutouts on an Elastic Foundation, Under Different Boundary and Partial Edge Loading Conditions

در مقاله كنوني، به بررسي كمانش ورق مستطيلي چندلايه ساخته شده از مواد مركب داراي دو سوراخ دايره اي طولي يا عرضي، مستقر بر روي بستر الاستيك ونكلر -پسترناك، پرداخته شده است. در اين راستا، از تئوري كلاسك ورق، روابط كرنش-جابجايي فن كارمن، روش هاي گلركين و انرژي و تبديل مسئله به مسئله مقادير ويژه استفاده شده است. بار كمانش براي موقعيت هاي مختلف نسبي سوراخ هاي ورق در بارگذاري هاي لبه اي موضعي: متمركز، يكنواخت و سينوسي، براي دو نوع شرط لبه اي جابجا شونده ساده و گيردار تعيين شده است.

In the present paper, buckling of multi-layer rectangular orthotropic composite plates with two longitudinal or transverse in-plane circular cutouts, on Winkler-Pasternak elastic foundation, is investigated. The analysis is accomplished through two steps. First, the in-plane pre-buckling stress components induced by the partial edge loads are determined and in the second stage, the Galerkin method is employed to develop the governing equations of the buckling. In this regard, the classical theory of plates, von Karman strain-displacement equations, Galerkin and energy approaches, and reduction of the problem to an eigenvalue problem are used. The buckling load is determined based on various relative locations of the cutouts and the: (1) uniform partial, (2) sinusoidal partial, and (3) concentrated edge loads, for the movable simply supported and clamped edge conditions. Furthermore, influence of the elastic foundation of the composite plate is investigated for different concentrated and partial loads. Results reveal that buckling of plates with holes or cutouts is dependent on opposite factors and may occur in local or global forms and the elastic foundation has pronounced effects of on the buckling load. This effect is more noticeable when the partial load is distributed on a larger length of the edge.