T-Stub Connection Component Tests James A Swanson and Roberto T Leon School of Civil and Environmental Engineering Georgia Institute of Technology Atlanta, Ga.

SAC Subtask 7.03 Tests on Bolted Connections Synthesis of existing data Testing: –Individual T-stubs and angles –Full-scale exterior-type connections Interpretation Design Recommendations Further testing

Approach Identify and quantify individual failure modes Assess influence of monotonic vs. cyclic loading Develop simplified models Calibrate with advanced FEM Provide design aids (?)

View of the Test Setup

 size of T-section or clip angle  size and number of bolts :  beam flange thickness  type of bolt Variables

Test Setup

Typical Tension Failure (little prying action)

Prying Deformations

Typical Tension Bolt Failures

Bolt Hole Elongation Prior to Failure

Net Section Failure

Block Shear Failure

Instrumentation A - relative slip B - stem uplift C - bolt uplift D - stem elongation E - overall elongation G - instrumented bolt E D C G B A

Connection Spring Model

T-Stub Spring Model ) Shear Bolts 5) Bearing Deformation 6) Connection Slip 1) Tension Bolts 2) Tee Flange 3) Tee Stem

TA-01 P/  Including Post Fracture Data Deformation (in) Load (kip) Deformation (mm) Load (kN)

Group 3 - P/  Deformation (in) Load (kip) Deformation (mm) Load (kN) TA-01 TA-02 TA-03 TA-04

Group 3 - P/Uplift Deformation (in) Load (kip) TA-01 TA-02 TA-03 TA-04 Deformation (mm) Load (kN)

TA-05 vs TA-07 P/  Deformation (in) Load (kip) TA-05 TA-07 Deformation (mm) Load (kN)

Group 1 Test Results "4"5"6"7"8" Tension Bolt Gage (in) Ultimate Load (kip) ActualEstimateDesign

TA-03 P/Bolt Force #3 Total Applied Load (kip) Bolt Force (kip) Total Applied Load (kN) Bolt Force (kN)

SAC Test FS-03 W21x44 beam W14 x 145 column T same as TD-01 7/8 in. A490 bolts

SAC FS-03: Initial view of top flange

SAC FS-03: Initial yielding in T and beam

SAC FS-03: Initial crack between last line of bolts

SAC FS-03: Final failure

Conclusions The spring model should work well in predicting stiffness characteristics. Net section fracture and block shear (after extensive yielding) are the most desirable failure modes because of their ductility. Component testing can provide a more economical means of testing than conventional full scale testing.

Acknowledgements The work presented here is funded by the Federal Emergency Management Association (FEMA) through a grant to SAC S tructural Engineers Association of California (SEAOC) A pplied Technology Council (ATC) C alifornia Universities for Research in Earthquake Engineering (CUREe)