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The following picture shows the ductility level selection screen for a structure with DTS = 1a and BYS = 5. According to 4.3.4.1 (a) , carrier systems with limited ductility level are not used for DTS = 1a . Besides, according to 4.3.4.1 (b) , for buildings with DTS 6 and DTS = 1a, mixed ductility load-bearing systems are not used. Since both items (a) and (b) are applied for a structure with DTS = 1a and BYS = 5, ductility level is limited and mixed options cannot be used in the TBDY 2018 Wizard.
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