Yazar "Apalak, Mustafa Kemal" seçeneğine göre listele

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    Öğe
    Effect of Composite Patch Geometry in Notched Plates Under Low Velocity Impact
    (Kırıkkale Üniversitesi, 2017) Çalışkan, Umut; Ekici, Recep; Apalak, Mustafa Kemal
    Therepair technique of the composite patch with bonding adhesive are used with thepurpose of repairing materials and increasing working life of the materials. Inthis study, the impact strength of notched metal materials repaired bycomposite patch investigated by numerically. Fiber reinforced laminatedcomposite patch was modeled by using finite element model. Composite patch wasbonded to damaged materials, and this structure was subjected to impact test. Thegeometrical and material non-linearities were considered in the explicitdynamic analysis. The notched plate was made of aluminum 6061-T6. The effects ofdesign parameters, such as composite patch geometry, on the impact energyabsorption of the plates were investigated. The metal notched plates weremodeled as a Johnson-Cook material model and the composite patches were modeledorthotropic elastic material model and Hashin damage. In the analysis results,the damage mechanisms of composite patch were exhibited and strength of damagedmaterials was exhibited in terms of contact force, kinetic energy and stressdistributions. The effect of patch geometries was also investigated in terms ofabsorbing impact energies. As the plates without patch perforated, repairedmetal notched plates with composite patch did not perforate.
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    Öğe
    Kompozit Yamalar ile Tamir Edilmiş Çatlaklı Sandviç Kirişlerin Eğilme Darbe Davranışları
    (Kırıkkale Üniversitesi, 2021) Caliskan, Umut; Ekici, Recep; Apalak, Mustafa Kemal
    Bu çalışma, deneysel ve sayısal olarak kompozit yamalar ile tamir edilen çatlaklı sandviç kirişlerin eğilme darbe davranışını araştırmaktadır. Sandviç kiriş elemanları yüzey tabakaları, cam elyaf takviyeli kompozit, köpük çekirdek, PVC malzeme ve yapıştırıcı tabakalardır. Üst yüzey tabakasına çatlak oluşturularak hasar verilmiştir ve kompozit yama yapıştırılarak tamir edilmiştir. Düşük hızlı darbe davranışı, farklı yama malzemeleri, kalınlıkları ve darbe enerjileri açısından incelenmiştir. Sayısal darbe analizleri, kompozit sandviç kirişin hasar davranışını modellemek ve deneysel darbe testi sonuçlarını karşılaştırmak için yapılmıştır. PYTHON program dili ile parametrik modelleneme yapılmıştır. Sonlu elemanlar alt programı ABAQUS-VUMAT kullanılarak 3B Hashin hasar modelleri kompozit yama ve yüzey tabakalarına uygulanmıştır. Son olarak, hasarlı kirişin eğilme rijitliği yama uygulaması ile artırılmıştır. Sandviç kirişlerin hasar toleransları, temas kuvveti değişimleri, kinetik enerji varyasyonları ve darbe sonrası hasar modları dikkate alınarak farklı yama parametreleri için belirlenmiştir.
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    Öğe
    Numerical Solution of Thermal Residual Stress Analysis with Finite Difference Method of Functionally Graded Circular Plates
    (Kırıkkale Üniversitesi, 2017) Demirbaş, Munise Didem; Apalak, Mustafa Kemal
    In this study, thermal residual stress analysis of functionally graded circular plates (FGCP) carried out. Finite difference equations are used in solving Navier's equations of elasticity and Fourier's heat conduction equation. The grading along the plate was made along the surface of plate and it was assumed that the material properties changed according to the Mori-Tanaka approach. Grading along the plate was made in both radial and tangential directions.  In this study, the effect of the coordinate derivatives of material properties was taken into consideration in both Fourier's heat conduction equation and Navier's equations of elasticity, unlike the other studies. As a result, when the materials compositions of FGCP were changed from ceramic-rich to metal-rich compositions, the stress levels were not affected considerably. The strain levels increased significantly when the metal compound in the material composition of FGCP was increased. FGCP are emphasized that the change of material properties due to two-dimensional significantly affect distributions of thermal strain and stress. In this study, it was emphasized that changing the radial and tangential direction of the compositional gradient exponents of FGCP subjected to heat flux along the outer edge significantly influences the strain and stress distributions.
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    Öğe
    Thermal Residual Stresses Analyses of Two-Dimensional Functionally Graded Circular Plates with Temperature-Dependent Material Properties
    (Kırıkkale Üniversitesi, 2018) Demirbaş, Munise Didem; Apalak, Mustafa Kemal
    In this study, thermal residual stress analysisof Functionally Graded Circular Plates joined with adhesive (FGCP-A) ispresented. Finite difference equations are used in solving Navier’s equations of elasticity and heat transfer. Thegrading along the plate is made along the surface of the plate. Material properties of the plate areinvestigated depending on the temperature dependent/independent and it isassumed that the temperature independent material properties changed accordingto the Mori-Tanaka approach. Grading along the plate is made in both radial andangular directions. and nbsp; In this study, the effects of temperature dependent/independent materialproperties and compositional gradient exponents on temperature, equivalentstrain and equivalent stress are compared. and nbsp;As a result, when considering the propertiesof the material depending on the temperature, the temperature, equivalentstress and strain distributions and levels vary considerably. Therefore, theproperties of the material dependent on the temperature must be taken intoconsideration in the analysis of thermal residual stress of materials used ashigh temperature material.