List of publications
Publication: Bidirectional behavior of structural clay tile infilled frames (1999)
Journal of structural engineering
Preparation and upload by:
Filip Anic, Faculty of Civil Engineering and Architecture Osijek, Josip Juraj Strossmayer University of Osijek
Publication abstract (click to enlarge):
Publication abstract (click to shrink):
Several bidirectional tests were performed on structural clay tile infilled steel frames to assess the interaction of in-plane and out-of-plane forces and to understand the behavior of damaged infills. Tests consisted of in-plane and out-of-plane uniform lateral load tests, out-of-plane drift tests, sequential tests (in-plane damage followed by out-of-plane loading, and out-of-plane damage foll
Several bidirectional tests were performed on structural clay tile infilled steel frames to assess the interaction of in-plane and out-of-plane forces and to understand the behavior of damaged infills. Tests consisted of in-plane and out-of-plane uniform lateral load tests, out-of-plane drift tests, sequential tests (in-plane damage followed by out-of-plane loading, and out-of-plane damage followed by in-plane loading), one combined inplane and out-of-plane test, and a seismic shake table test.
The infills are usually analyzed by evaluating the effect of inplane and out-of-plane forces independently. The in-plane behavior of infills has been widely studied. Most research on out-of-plane loading of masonry infills has centered on uniform panel loads that attempt to emulate wind or inertial effects of the wall.
AIM AND SCOPE
To test different combinations of loadings; namely, simultaionus, IP+OoP and OoP+IP. By airbag and interstorey-drift methods.
DESIGN AND CONSTRUCTION OF THE TEST SPECIMENS:
The specimens consisted of steel columns bent in-plane about the weak axis and a steel beam connected to the column using double clip angles. The infill was constructed with nominal 200 x 300 x 300 mm structural clay tile units and type N masonry cement mortar. The clay tiles were laid with their cores horizontal (side construction) using approximately 19 mm full bed joints, and only face shell mortar in the head joints. Each infill was bonded to the column and beam by snugly packing mortar between the steel and the tile. Mortar was not placed between the panel and the flanges of the enclosing columns. No reinforcement was used in the masonry.
The first tests evaluated the in-plane strength and the out-of-plane capacity under uniform loading for three different infill thicknesses. The interaction with in-plane loads was determined by two sequential tests (in-plane damage followed by out-of-plane loading, and out-of-plane damage followed by in-plane loading), and one combined in-plane and out-of-plane test. Two tests were performed in which the infill was first subjected to out-of-plane drift loads, followed by in-plane loading. The results of these tests are compared to a shake table test that subjected an infill wall specimen to out-of-plane loading.
Unreinforced masonry panels have significant out-of-plane stability under both inertial (uniform) loads and imposed drift loads. This is primarily due to arching, or the development of in-plane membrane forces. Provided there is an in-plane restraint so that arching can develop, only very tall panels, or very thin panels (high h/t ratios) may be vulnerable to loss of stability under inertial loads. The infill panels also appear capable of handling large drift displacements (1–2%).
The interaction of in-plane and out-of-plane forces was not significant, particularly at moderate levels of loading. The primary effect of sequential loading is loss of stiffness, rather than loss of strength. Prior out-of-plane loadings may eliminate the diagonal cracking in-plane limit state. However, there appears to be little effect on the corner crushing limit state. Prior in-plane loading appears to result in higher deflections under uniform lateral loads. Some strength decrease may result, but arching can still form, resulting in substantial capacity.
A combined in-plane racking and uniform lateral load test resulted in reduced lateral pressure capacity. Lateral loads producing thrust forces around the panel perimeter and in-plane loads producing strut forces along the diagonal combined, creating high vertical compression near the panel base and causing failure of the bottom course tiles. However, even after much damage to the masonry panel, the infill remained remarkably stable under combined loading and was adding to in-plane strength of the system.
RECOMMENDATIONS FOR FUTURE RESEARCH
None were specified.
Test setup: Effect of Prior In-Plane Loading on Out-of-Plane Response
Experiment: Frame 19 - envelope
Derived from this publication
- Concrete strength:
- Steel strength:
- Masonry strength:
- 5.6 MPa
- Concrete young modulus:
- Steel young modulus:
- 199948 MPa
- Masonry young modulus:
- 5300 MPa
- Area moment of inertia:
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