Di Malaysia, hampir semua rumah di kawasan luar bandar adalah struktur bukan kejuruteraan. Bumbung rumah-rumah ini adalah mudah terdedah kepada kegagalan dan pelbagai jenis kegagalan bumbung boleh dijangka. Kajian ini mengkaji kapasiti tarik-keluar daripada beberapa hubungan mudah bertujuan untuk mengikat purlin kayu itu kepada kasau. Jenis-jenis sambungan adalah paku, dua paku, paku ditambah logam tali dan paku serta tali. Ujian telah dijalankan pada jenis kayu Damar Minyak dan Dark Red Meranti, kedua-duanya diklasifikasikan di bawah kumpulan kekuatan 5 dan 6. Beban angin telah digunakan dalam bentuk daya tarik keluar dijana melalui rangka dalam seperti rumah dan ujian Mesin Universal. Hasil kajian menunjukkan bahawa, untuk sambungan paku, dua fasa tindak balas diperhatikan. Lain-lain jenis sambungan menunjukkan tiga fasa yang berbeza dari awal sehingga gagal. Fenomena ini terutamanya benar bagi kedua-dua jenis kayu. Dalam hal jenis kayu Damar Minyak, kapasiti tarik keluar maksimum dipamerkan oleh paku dan logam sambungan tali (1.55 kN) diikuti dengan paku dan tali (1.485 kN), dua paku (0.825 kN) dan paku (0.445 kN). Walau bagaimanapun, untuk jenis kayu Dark Red Meranti, penggunaan dua paku yang berjarak 30 mm selain dipamerkan tarik keluar kapasiti tertinggi (2.5 kN) diikuti dengan paku dan tali logam (1.8 kN), paku dan tali (1.53 kN) dan paku sahaja (1.22 kN). Ia juga menyatakan bahawa gred kayu kuat dibangunkan kuku yang lebih tinggi untuk sambungan kayu berbanding gred kayu yang lebih rendah. Sambungan paling berkesan untuk jenis kayu Damar Minyak dan Dark Red Meranti didapati paku serta tali dan dua paku, masing-masing.
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In Malaysia, almost all houses in rural area are non-engineered structures. The roof of these houses is susceptible to failure and many types if roofing failure can be expected. This study examines the pull-out capacity of several simple connections meant for tying the timber purlin to rafter. The types of connections are single nail, double nail, nail plus metal strap and nail plus rope. The tests were conducted on timber type Damar Minyak and Dark Red Meranti, both are classified under strength group 5 and 6. The wind load was applied in the form of pull-out force generated via in-house frame and Universal Testing Machine. The results showed that, for single nail connection, two phases of response were observed. Other types of connections showed three distinct phases from beginning until failure. This phenomenon is particularly true for both types of timber. In the case of timber type Damar Minyak, the maximum pull-out capacity exhibited by the nail and metal strap connection (1.55 kN) followed by nail and rope (1.485 kN), double nail (0.825 kN) and single nail (0.445 kN). However, for timber type Dark Red Meranti, the use of double nail spaced at 30 mm apart exhibited the highest pull-out capacity (2.5 kN) followed by nail and metal strap (1.8 kN), nail and rope (1.53 kN) and single nail (1.22 kN). It was also noted that stronger timber grade developed higher nail to timber connection compared to lower timber grade. The most efficient connection for timber type Damar Minyak and Dark Red Meranti was found to be nail plus rope and double nail, respectively.
Experimental investigation on the load carrying capacity of modified purlin to rafter connection / Sheikh Hazwan Humayunkabir