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## entrFundamental Frequency Optimization of Doubly Curved Aerospace Structural Panels via Variable Stiffness ConceptDeğişken Sertlik Konsepti ile Havacılık ve Uzay Çift Eğimli Panel Yapılarının Temel Frekans Optimizasyonu

#### Touraj FARSADİ [1] , Hasan KURTARAN [2]

In the present study, the fundamental natural frequencies of curvilinear fiber composite doubly curved panel are optimized. Doubly curved panels are used in various components of the structural frames of the aerospace vehicles. The variable stiffness behavior is obtained by altering the fiber angles continuously according to curvilinear fiber path function in the composite laminates. Structural model is utilized based on the virtual work principle. The aim is to achieve the best fiber paths with maximized fundamental frequencies or in-plane strengths for a composite panels. An eight-layer composite doubly curved panel with two types of boundary conditions are considered as a case study in this research. The boundary conditions include; CCCC, FCFC where C stands for clamped, and F for free edges. Von-Karman kinematic strain relations are used and the first order shear deformation theory (FSDT) is employed to generalize the formulation for the moderately thick doubly curved panel including transverse shear effects. Generalized Differential Quadrature (GDQ) method of solution is employed to solve the governing equations of motion. Numerical results demonstrate the effectiveness fiber angle path and boundary conditions on the natural frequencies of the composite panel. The optimal fiber angle paths of each layer are presented for the above cases in free vibration analysis.
Bu çalışmada, eğrisel fiber kompozit çift eğimli panelin temel doğal frekansları optimize edilmiştir. Hava-uzay araçlarının yapısal çerçevelerinin çeşitli bileşenlerinde çift kıvrımlı paneller kullanılmaktadır. Değişken sertlik davranışı, kompozit laminatlarda eğrisel fiber yol fonksiyonuna göre fiber açılarının sürekli olarak değiştirilmesiyle elde edilir. Yapısal model sanal çalışma prensibine dayalı olarak kullanılmaktadır. Amaç, kompozit paneller için maksimize edilmiş temel frekanslar veya düzlem içi güçler ile en iyi fiber yollarını elde etmektir. Bu araştırmada, iki tür sınır koşuluna sahip sekiz katmanlı bir kompozit çift eğimli panel bir vaka çalışması olarak kabul edilir. Sınır koşulları şunları içerir; CCCC, FCFC burada C kelepçeli anlamına gelir ve F serbest kenarlar için. Von-Karman kinematik gerinim ilişkileri kullanılır ve enine kesme etkileri dahil orta derecede kalın çift eğimli panel için formülasyonu genelleştirmek için birinci dereceden kesme deformasyon teorisi (FSDT) kullanılır. Genelleştirilmiş Diferansiyel Quadrature (GDQ) çözüm yöntemi, hareketin yönetim denklemlerini çözmek için kullanılır. Sayısal sonuçlar, kompozit panelin doğal frekansları üzerindeki fiber açı yolu ve sınır koşullarının etkinliğini gösterir. Her katmanın optimum fiber açısı yolları, yukarıdaki durumlar için serbest titreşim analizinde sunulmuştur.
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Primary Language en Engineering, Aerospace Research Articles Orcid: 0000-0002-9363-3805Author: Touraj FARSADİ (Primary Author)Institution: ADANA SCIENCE AND TECHNOLOGY UNIVERSITYCountry: Turkey Orcid: 0000-0002-2552-8616Author: Hasan KURTARANInstitution: ADANA SCIENCE AND TECHNOLOGY UNIVERSITYCountry: Turkey Application Date : August 28, 2020 Acceptance Date : December 26, 2020 Publication Date : December 28, 2020
 Bibtex @research article { jav787455, journal = {Journal of Aviation}, issn = {}, eissn = {2587-1676}, address = {journalofaviation@gmail.com}, publisher = {Vedat Veli ÇAY}, year = {2020}, volume = {4}, pages = {36 - 47}, doi = {10.30518/jav.787455}, title = {Fundamental Frequency Optimization of Doubly Curved Aerospace Structural Panels via Variable Stiffness Concept}, key = {cite}, author = {Farsadi, Touraj and Kurtaran, Hasan} } APA Farsadi, T , Kurtaran, H . (2020). Fundamental Frequency Optimization of Doubly Curved Aerospace Structural Panels via Variable Stiffness Concept . Journal of Aviation , 4 (2) , 36-47 . DOI: 10.30518/jav.787455 MLA Farsadi, T , Kurtaran, H . "Fundamental Frequency Optimization of Doubly Curved Aerospace Structural Panels via Variable Stiffness Concept" . Journal of Aviation 4 (2020 ): 36-47 Chicago Farsadi, T , Kurtaran, H . "Fundamental Frequency Optimization of Doubly Curved Aerospace Structural Panels via Variable Stiffness Concept". Journal of Aviation 4 (2020 ): 36-47 RIS TY - JOUR T1 - Fundamental Frequency Optimization of Doubly Curved Aerospace Structural Panels via Variable Stiffness Concept AU - Touraj Farsadi , Hasan Kurtaran Y1 - 2020 PY - 2020 N1 - doi: 10.30518/jav.787455 DO - 10.30518/jav.787455 T2 - Journal of Aviation JF - Journal JO - JOR SP - 36 EP - 47 VL - 4 IS - 2 SN - -2587-1676 M3 - doi: 10.30518/jav.787455 UR - https://doi.org/10.30518/jav.787455 Y2 - 2020 ER - EndNote %0 Journal of Aviation Fundamental Frequency Optimization of Doubly Curved Aerospace Structural Panels via Variable Stiffness Concept %A Touraj Farsadi , Hasan Kurtaran %T Fundamental Frequency Optimization of Doubly Curved Aerospace Structural Panels via Variable Stiffness Concept %D 2020 %J Journal of Aviation %P -2587-1676 %V 4 %N 2 %R doi: 10.30518/jav.787455 %U 10.30518/jav.787455 ISNAD Farsadi, Touraj , Kurtaran, Hasan . "Fundamental Frequency Optimization of Doubly Curved Aerospace Structural Panels via Variable Stiffness Concept". Journal of Aviation 4 / 2 (December 2020): 36-47 . https://doi.org/10.30518/jav.787455 AMA Farsadi T , Kurtaran H . Fundamental Frequency Optimization of Doubly Curved Aerospace Structural Panels via Variable Stiffness Concept. JAV. 2020; 4(2): 36-47. Vancouver Farsadi T , Kurtaran H . Fundamental Frequency Optimization of Doubly Curved Aerospace Structural Panels via Variable Stiffness Concept. Journal of Aviation. 2020; 4(2): 36-47. IEEE T. Farsadi and H. Kurtaran , "Fundamental Frequency Optimization of Doubly Curved Aerospace Structural Panels via Variable Stiffness Concept", Journal of Aviation, vol. 4, no. 2, pp. 36-47, Dec. 2021, doi:10.30518/jav.787455

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