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b. Strengthened Simulations. The patterns of reinforcement included horizontal, vertical, diagonal and combined . Figure 8 shows stress and reinforcement slippage results obtained for horizontal reinforcement with and without cohesion effects
included in the mortar (No.3 and No. 11 respectively). In the more realistic case with cohesion, the introduction of reinforcement has lead to more damage. Without cohesion but with µ=0.6, less damage occurs and good correlation is obtained with
earlier simulations (Brookes, Mehrkar-Asl, 1998). The following reasons are likely for this behaviour:
(1) With cohesion, less energy is dissipated across the joints leading to less structural damping.
(2) Increased shear capacity across joints provided by cohesion helps a rocking mechanism develop in the wall. This mechanism causes sudden vertical oscillations of the wall above the reinforcement leading to additional damage.
(3) Axial slippage of reinforcement in excess of 5mm indicates that bond with the masonry has failed. The graphs show progressive bond failure at both ends of the reinforcement. As with the masonry, less damage occurs to the reinforcement when
no cohesion is considered.
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