Shear wall has been used extensively as the major lateral resistant system in structural design due to its large in-plane rigidity. Sometimes, perforated shear wall is needed because of architectural or practical needs. A single shear wall is then divided into several individual walls connected by a series of beams along the story height. This system is referred as coupled shear wall system and beams used to connect two walls are referred as coupling beams.

When coupled shear wall system is subjected to earthquake-type lateral load, shear forces transferred by coupling beams create tensile and compressive actions in the individual shear wall; also referred as coupled action, which counteracts a portion of overturning moments and hence, reduces the moment demand in the individual shear wall. An ideal coupled shear wall system is similar to a framed structure where plastic hinges are expected to form in most of coupling beams over the entire height of the structure, followed by yielding at the base of each shear wall. To achieve the prescribed advantages of coupled wall system, coupling beams must sustain the designed shear forces and satisfactory energy dissipation abilities under large displacement reversals. For reinforced concrete coupled wall system, several researches (Paulay and Binney, 1974; Shiu et al., 1978) have found that diagonal reinforcements are necessary for coupling beams with span to depth ratio less than 2. However, the construction of this diagonal reinforcement create considerable steel congestions both in coupling beam itself and special boundary zone of shear wall. Alternative solutions have been studied in many researches. Among all, hybrid coupled shear wall system has been discussed widely (Harries et. al., 1993; El-Tawil et. al. 2010). Most of hybrid coupled shear wall system use steel coupling beam. Experimental results confirmed that steel web yielding in shear can provide satisfactory hysteretic response (Harries, 2001). However, the installation of embedded steel coupling beam into boundary zone of the shear wall creates another construction challenge.

In this research, using LYP steel plate as a cost-effective solution for new coupling beam design is proposed. A recent study conducted by Chen and Yen (2008) and Chen and Jhang (2000) demonstrated that shear panel using steel plate with low yield point (LYP) exhibit excellent deformation and energy dissipation capacities. Two half-scaled coupled shear wall specimens were tested in this research. Specimen CW – RC consists of two reinforced concrete shear walls and four diagonally reinforced concrete coupling beams while Specimens CW – S consists of two reinforced concrete shear walls and four steel coupling beams featuring LYP steel web in the middle. Based on the experimental result, the Specimen CW – RC has a better displacement ductility and higher initial stiffness compare to Specimen CW – S. It is also observed that a ductile behavior of coupled shear wall can be achieved if the shear wall is properly proportioned to a ductile coupling beam.

Shear wall has been used extensively as the major lateral resistant system in structural design due to its large in-plane rigidity. Sometimes, perforated shear wall is needed because of architectural or practical needs. A single shear wall is then divided into several individual walls connected by a series of beams along the story height. This system is referred as coupled shear wall system and beams used to connect two walls are referred as coupling beams.

When coupled shear wall system is subjected to earthquake-type lateral load, shear forces transferred by coupling beams create tensile and compressive actions in the individual shear wall; also referred as coupled action, which counteracts a portion of overturning moments and hence, reduces the moment demand in the individual shear wall. An ideal coupled shear wall system is similar to a framed structure where plastic hinges are expected to form in most of coupling beams over the entire height of the structure, followed by yielding at the base of each shear wall. To achieve the prescribed advantages of coupled wall system, coupling beams must sustain the designed shear forces and satisfactory energy dissipation abilities under large displacement reversals. For reinforced concrete coupled wall system, several researches (Paulay and Binney, 1974; Shiu et al., 1978) have found that diagonal reinforcements are necessary for coupling beams with span to depth ratio less than 2. However, the construction of this diagonal reinforcement create considerable steel congestions both in coupling beam itself and special boundary zone of shear wall. Alternative solutions have been studied in many researches. Among all, hybrid coupled shear wall system has been discussed widely (Harries et. al., 1993; El-Tawil et. al. 2010). Most of hybrid coupled shear wall system use steel coupling beam. Experimental results confirmed that steel web yielding in shear can provide satisfactory hysteretic response (Harries, 2001). However, the installation of embedded steel coupling beam into boundary zone of the shear wall creates another construction challenge.

In this research, using LYP steel plate as a cost-effective solution for new coupling beam design is proposed. A recent study conducted by Chen and Yen (2008) and Chen and Jhang (2000) demonstrated that shear panel using steel plate with low yield point (LYP) exhibit excellent deformation and energy dissipation capacities. Two half-scaled coupled shear wall specimens were tested in this research. Specimen CW – RC consists of two reinforced concrete shear walls and four diagonally reinforced concrete coupling beams while Specimens CW – S consists of two reinforced concrete shear walls and four steel coupling beams featuring LYP steel web in the middle. Based on the experimental result, the Specimen CW – RC has a better displacement ductility and higher initial stiffness compare to Specimen CW – S. It is also observed that a ductile behavior of coupled shear wall can be achieved if the shear wall is properly proportioned to a ductile coupling beam.

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