Shake table tests of three storey cold-formed steel structures with strap-braced walls

The unconventionality of the cold-formed steel (CFS) structures raised, in recent times, a lot of interest from many national and international companies resulting in the promotion of experimental activity with the main aim of investigating the seismic behaviour of these systems. In this perspective, a research project carried out at the University of Naples “Federico II” and funded by Lamieredil S.p.A. company started in the last years. The study included an extended experimental campaign, involving shake table tests on two three-storey prototypes in reduced scale (1:3). The investigated lateral load resisting systems were CFS strap-braced stud walls, designed as low dissipative seismic structures. The present paper illustrates case study, prototypes, test program and main shake table tests results.

Download Full-text

Shake Table Testing of Standard Cold-Formed Steel Storage Rack

Applied Sciences ◽

10.3390/app11041821 ◽

2021 ◽

Vol 11 (4) ◽

pp. 1821

Author(s):

Ahmad Firouzianhaji ◽

Nima Usefi ◽

Bijan Samali ◽

Peyman Mehrabi

Keyword(s):

Ground Motion ◽

Concrete Block ◽

Design Guidelines ◽

Full Scale ◽

Experimental Program ◽

Shake Table ◽

Shake Table Tests ◽

Actual Performance ◽

Cold Formed Steel ◽

The Time Domain

Full-scale shake table investigations are strongly required to understand the actual performance of storage racks and to improve the rack design guidelines. This paper presents the results of full-scale shake table tests on New Zealand standard storage rack frames with two-bay and two-level to determine the dynamic characteristics of a standard rack structure and to measure the damping of the system. The experimental program was conducted in three phases. First, the identification parameters including the natural frequency and damping of the system were determined through a series of preliminary tests. Then, shake table tests were performed to capture the inelastic response of rack frames under low to medium intensities of El-Centro ground motion. Finally, the shake-table tests were repeated with scaling down the time domain and broader ranges of ground motion intensities to consider the performance of taller rack systems. In addition, a comprehensive discussion on the damping of the system is also provided based on the test results. The performance of the rack frame is described through an extensive set of measurements, including rack displacement, pallet sliding, the acceleration of a concrete block and rack frame and the damping of the system in the down-aisle direction. The results indicate that the standard rack frames are able to endure large inelastic deformations without loss of stability.

Download Full-text

Numerical Modelling of CFS Three-Story Strap-Braced Building under Shaking-Table Excitations

Materials ◽

10.3390/ma14010118 ◽

2020 ◽

Vol 14 (1) ◽

pp. 118

Author(s):

Alessia Campiche

Keyword(s):

Numerical Modelling ◽

Seismic Behavior ◽

Numerical Models ◽

Dynamic Properties ◽

Shaking Table ◽

Shake Table ◽

Shake Table Tests ◽

Research Activities ◽

Story Drift ◽

Cold Formed Steel

In recent research activities, shake-table tests were revealed to be useful to investigate the seismic behavior of cold-formed steel (CFS) buildings. However, testing full-scale buildings or reduced-scale prototypes is not always possible; indeed, predicting tools and numerical models could help designers to evaluate earthquake response. For this reason, numerical modelling of two strap-braced prototype buildings, recently tested on shake-table at University of Naples Federico II in cooperation with Lamieredil S.p.A. company, was developed. The models were validated trough the comparison between experimental and numerical results, in term of dynamic properties (fundamental period of vibration and modal shapes), peak roof drift ratios and peak inter-story drift ratios. Although dynamic properties of mock-ups were captured with accuracy by the developed models, the comparison highlighted the need to consider accumulation of damage and rocking phenomenon in the modelling to capture with good accuracy the seismic behavior of CFS strap-braced building, subjected to high intensity records.

Download Full-text

Seismic Behavior of Brick Cave Dwellings: Shake Table Tests

Journal of Building Engineering ◽

10.1016/j.jobe.2021.102886 ◽

2021 ◽

pp. 102886

Author(s):

Jianyang Xue ◽

Pengchun Hu ◽

Fengliang Zhang ◽

Yan Zhuge

Keyword(s):

Seismic Behavior ◽

Shake Table ◽

Shake Table Tests

Download Full-text

Shake table test program of cold-formed steel in-plane partition walls

Structures ◽

10.1016/j.istruc.2021.01.026 ◽

2021 ◽

Vol 30 ◽

pp. 503-517

Author(s):

Hyung-Joon Kim ◽

Dong-Hyeon Shin

Keyword(s):

Shake Table Test ◽

Plane Partition ◽

Shake Table ◽

Test Program ◽

Partition Walls ◽

Cold Formed Steel

Download Full-text

Comparison of Failure Modes of Piping Systems With Wall Thinning Subjected to In-Plane, Out-of-Plane, and Mixed Mode Bending Under Seismic Load: An Experimental Approach

Journal of Pressure Vessel Technology ◽

10.1115/1.4001517 ◽

2010 ◽

Vol 132 (3) ◽

Cited By ~ 12

Author(s):

Izumi Nakamura ◽

Akihito Otani ◽

Masaki Shiratori

Keyword(s):

Dynamic Behavior ◽

Failure Modes ◽

Seismic Load ◽

Piping System ◽

Shake Table ◽

Shake Table Tests ◽

Wall Thinning ◽

Piping Systems ◽

Out Of Plane ◽

Plane Bending

Pressurized piping systems used for an extended period may develop degradations such as wall thinning or cracks due to aging. It is important to estimate the effects of degradation on the dynamic behavior and to ascertain the failure modes and remaining strength of the piping systems with degradation through experiments and analyses to ensure the seismic safety of degraded piping systems under destructive seismic events. In order to investigate the influence of degradation on the dynamic behavior and failure modes of piping systems with local wall thinning, shake table tests using 3D piping system models were conducted. About 50% full circumferential wall thinning at elbows was considered in the test. Three types of models were used in the shake table tests. The difference of the models was the applied bending direction to the thinned-wall elbow. The bending direction considered in the tests was either of the in-plane bending, out-of-plane bending, or mixed bending of the in-plane and out-of-plane. These models were excited under the same input acceleration until failure occurred. Through these tests, the vibration characteristic and failure modes of the piping models with wall thinning under seismic load were obtained. The test results showed that the out-of-plane bending is not significant for a sound elbow, but should be considered for a thinned-wall elbow, because the life of the piping models with wall thinning subjected to out-of-plane bending may reduce significantly.

Download Full-text