Experimental study of composite column and wall systems for impact resistance

Transcription

1 Experimental study of composite column and Dipl.-Ing. Alexander Britner Abteilung Stahl- und Leichtmetallbau Leitung: Prof. Dr.-Ing. T. Ummenhofer KIT Universität des Landes Baden-Württemberg und nationales Forschungszentrum in der Helmholtz-Gemeinschaft

2 Motivations Design of buildings which need to resist extreme loads like blast and impact becomes more important Composite column and composite wall systems made of high performance steel and concrete can be suited for such loads Available design rules are not appropriate for these composite systems made of high performance materials The knowledge of the behaviour of composite columns and wall systems in case of extreme dynamic loads is poor Type 1.1 Type 1.3 Type 2 Composite wall system Composite column Dipl.-Ing. Alexander Britner Experimental study of composite column and

3 Objective Assessment of the dynamic response of composite columns and wall systems General behaviour and suitability Composite behaviour Ductility and dissipation of energy Assessment of the damages related to fire resistance Development of working tools and guides for the design of composite columns and wall systems The experimental study was performed within a RFCS project COSIMB Dipl.-Ing. Alexander Britner

4 Impact Tests Samples Materials Steel S460 Concrete C40/50 Reinforcement S500 d = 6mm / 3.8cm²/m d = 12mm / 18.8cm²/m d = 8mm headed studs d = 16mm / 33,5cm²/m Steel Section HEA140 Composite wall system Length 3.4 m (clear span 3.0 m) d = 8mm headed stud d = 13mm Composite column

5 Impact Tests Experimental Set-up Single span girder Simply supported Clear span 3.0 m Stiffness of the impact body relates to a van Impact Moving Barrier mounted sample

6 Impact Tests test impact velocity mass of the deflection in the midspan max. load IMB max. residual [m/s] [kg] [kn] [mm] [mm] column wall system

7 Load [kn] Impact Tests Time - impact force - diagram measured linearised V = m/s V = 9.89 m/s V = 7.42 m/s kn 556 kn 557 kn 400 Load level Column 155 kn 360 kn 376 kn 255 kn Time [ms]

8 Impact Tests Sudden crack propagation in the mid-span Crack propagation corresponds in time with the load decrease

9 Load [kn] Impact Tests Sudden crack propagation in the mid-span propagation corresponds in time with the load decrease measured linearised V = m/s V = 9.89 m/s V = 7.42 m/s kn 556 kn 557 kn 400 Load level Column 155 kn 360 kn 376 kn 255 kn Time [ms]

10 Impact Force Impact Tests FE-Analysis For understanding the impact force propagation FE analysys with three different mechanical models was done Model 1: performed tests 400 I II III 300 unsupported Model 2: no supports weightless 200 Model 3: no mass 100 supported time [ms]

11 Load [kn] Impact Tests Load peak: inertia forces First load level: static load capacity Second laod level: residual capacity measured linearised V = m/s V = 9.89 m/s V = 7.42 m/s kn 556 kn 557 kn 400 Load level Column 155 kn 360 kn 376 kn 255 kn Time [ms]

12 Summary The residual capacity of the composite walls is much higher than the capacity of a composite column. No slip between the concrete slab and the steel section could be determined. The composite columns and wall systems showed high ductility

13 Conclusion The overall response, especially the residual capacity and high ductility demonstrates the outstanding qualification of composite column and wall systems for effective protection against impact loads. The results of this study are an important step towards rational design concept for composite columns and wall systems

14 Thank you very much for your attention!