Sandalye yan çerçeve birleştirmelerinde yarı rijitlik katsayılarının nümerik analiz sonuçlarına etkileri

Öz

Bu çalışmada, sandalye yan çerçeve birleştirmelerine ait yarı rijitlik katsayılarının belirlenmesi ve sonlu elemanlar yöntemiyle (FEM) gerçekleştirilen nümerik analizlerde kullanılması amaçlanmıştır. Deney örneklerinin hazırlanmasında Doğu kayını (Fagus orientalis L.) ve sarıçam (Pinus sylvestris L.); birleştirme tekniği olarak da kavelalı-tutkallı birleştirme tercih edilmiştir. Yan çerçeve birleştirmelerini temsilen, T-tipi ve L-tipi örnekler farklı çap ve boyda kavelalar kullanılarak hazırlanmış ve yarı rijitlik katsayıları üzerinde bu faktörlerin etkileri belirlenmiştir. Örneklere statik eğilme testi uygulanmış ve moment-rotasyon grafiklerinin elastik bölgesine göre yarı rijitlik katsayıları belirlenmiştir. Daha sonra yarı rijitlik katsayıları kullanılarak nümerik analizler gerçekleştirilmiş ve birleştirmelerin rijit ya da yarı rijit tanımlanmasının, sistemin moment dağılımı ve yer değiştirmeler üzerindeki etkisi belirlenmiştir. Çalışma sonucunda, yarı rijitlik katsayıları yüksek olan birleştirmelerde, yer değiştirme değerlerinin düştüğü ve daha az deformasyon olduğu anlaşılmış olup bu sonuçlar birleştirme deneylerinden elde edilen deformasyon karakteristikleri ile tutarlıdır. En yüksek yarı rijitlik katsayıları, 10 × 35 veya 40 mm (4905 Nm/rad) kavelalarla birleştirilen Doğu kayını birleştirmelerde elde edilirken, en düşük değerler ise 8 × 40 mm (1892 Nm/rad) kavelalarla birleştirilen Sarıçam birleştirmelerde elde edilmiştir.

Anahtar Kelimeler

• Sandalye çerçevesi
• Nümerik analiz
• Yarı rijitlik katsayısı

Effects of the semi-rigidity coefficients on numerical analysis results in chair side frame joints

Öz

In this study, it is aimed to determine the semi-rigidity coefficients related to joints of chair side frame and to use them numerical analyses with finite element method (FEM). Turkish beech (Fagus orientalis L.) and Scotch pine (Pinus sylvestris L.) were used for preparing the specimens; and glued dowel joint was preferred as jointing technique. T-type and L-type specimens were utilized for representing the side frame joints. Different diameters and lengths of dowels were used in the specimens, and effects of dowel these factors on semi-rigidity coefficients of joints were determined. Specimens were tested under static bending and semi-rigidity coefficients were determined by considering the elastic region of moment-rotation graphs. Then, numerical analyses were performed using these semi-rigidity coefficients and effect of defining the joints as rigid or semi-rigid on moment distribution and deflections at the joints was determined. As a result of study, it was understood that the chairs consisting of joints with high semi-rigidity coefficients, deflections decreased and joints deformed less, and these results were consistent with the deformation charactheristics results obtained from real tests. The highest semi-rigidity coefficients were obtained from the Turkish beech T-type joints connected with 10 × 35 or 40 mm (4905 Nm/rad) dowels while the lowest values were obtained from the Scotch pine L-type joints connected with 8 × 40 mm (1892 Nm/rad) dowels.

Anahtar Kelimeler

• Chair frame
• Numerical analysis
• Semi-rigidity coefficients

Kaynakça

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