Vertical (axial) stiffness = 10,000 k/in (linear) Initial shear stiffness = 100 k/in Shear yield force = 40 kips Ratio of post yield shear stiffness to initial shear stiffness = | Problem Q Three Frames Concrete E 5000 ksi Poissons Ratio Beams 24 wide by 36 deep Columns 24 by 24 Damper Properties Linear Properties Effective stiffness 0 k in Effective damping 0 k-sec in Nonlinear Properties Stiffness 1000 k in Damping 30 k-sec in Damping exponent Isolator Properties Isolator1 Vertical axial stiffness 10 000 k in linear Initial shear stiffness 100 k in Shear yield force 40 kips Ratio of post yield shear stiffness to initial shear stiffness Time History Apply the ELCENTRO record. Three time and acceleration values are given on each line of this file. The acceleration value is in units of g. The length of the record is seconds. To Do Create three frames one bare one with dampers and one with isolators. Create a video .avi file of the nonlinear time history run. Review the mode shapes. Include a 50 kip point load and a kip-sec2 in point mass at each 2nd 3rd and roof level joint of each frame Roof 24 24 Dampers at all levels in this frame 24 Rubber isolators at base of this frame 3rd OJ 24 2nd Base 24 Note Our intent is that you try this problem on your own first. After you have solved it on your own you can step through our solution if desired. If you have problems trying to create the model then follow the steps in our solution. 1 Problem Q Solution 1. 2. 3. Click the drop down box in the status bar to change the units to kip-ft. Kip-ft 30 From the File menu select New Model From Template. This displays the Model Templates dialog box In this dialog box click on the Portal Frame template Portal Frame dialog box button to display the 4. In this dialog box Type 3 in the Number of Stories edit box. Type 5 in the Number of Bays edit box. Uncheck the Restraints check box. Click the OK button. 5. Click the X in the top right-hand corner of the 3-D View window to close it. 6. Click the Set Elements button I Ẽ3 I on the main toolbar or select Set Elements. from the View menu to
