Shake Table Demonstration Test on 3 Storey Steel Frame Structures

To perform dynamic shake table test on 3 storey 3D steel frame structures at the Earthquake Engineering Center of UET Peshawar. This experiment will be conducted as part the Earthquake Engineering Course CE 5163 Computer Applications to Structural Engineering. The test will be attended by subject students (MSc/PhD) and other students (UG/PG) interested in the subject.

Aims and Objectives

The following are the objectives of the dynamic shake table test:

1. Understand conducting shake table test on the seismic simulator using white-noise and real acceleration record (spectrum-compatible per the code recommendation).

2. Carryout model identification of structure: computation of modal periods, modal shapes, using white-noise signal.

3. Compute base shear demand on the structure for the acceleration record run.4. Test the structure under increasing intensity (linear scaling of accelerogram).5. Comparison of the experimental base shear with the calculated shear obtained using a)-

code-based Equivalent Static Load Method b)- Response Spectrum Analysis Method. 6. Numerical modeling & calibration of the frame using SeismoStruct (Finite Element Based

Seismic Analysis Software).

Experimental Programme

Requirements: Instrument and Tools, Support Staff

Following are the requirements to perform the shake table test:

1. White-Noise Signal, to be provided by the student after design the signal from sine fucntions.

2. Real spectrum compatible acceleration record, to be provided by student.3. Seismic Simulator (Shake Table 1.5m x 1.5m, Data Acquisition System and

Accessories).4. Instruments for data collection: (3 accelerometers, 3 displacement transducers).5. Supporting staff to help on the specimen mounting, instrument installation, data

collection.

Testing Program

The test will be performed in the following manner

1. Run the analysis using White-Noise Signal and record floors displacement and acceleration.

2. Perform Ten sets of run using scaled acceleration time history and record floors displacement and acceleration.

Data Processing and Analysis

The data collected will be processed and analyzed in the following manner

1. Single processing of the floor response acceleration will be performed to obtain the modal frequencies.

2. Modal shapes will be obtained from floor displacement response and/or from the amplitude ratios of the FFT of acceleration response at the fundamental frequencies i.e. observed peaks in the FFT spectra.

3. The base shear will be calculated by multiplying the floor masses with the floor response acceleration (to obtain the floor inertial forces), summing all the floor inertial forces will provide estimate of base shear force.

CE 5163 Computer Applications to Structural EngineeringCourse Instructor: Dr. Naveed Ahmad, EEC, UET Peshawar.