Study on shear behavior of head enlarged anchorage connector used in LEM-filled CFS shear wall to floor connection

Lightweight EPS material (LEM)-filled cold-formed steel (CFS) shear wall structures may exhibit dis-continuities in shear transfer for their vertical lateral force-resisting elements. To investigate the shear performance of the head enlarged anchorage (HEA) connector used in LEM-filled CFS shear wall-to-floor connections, shear push-out tests were conducted on five specimens. The effects of embedment depth, LEM strength, and enlarged end area on the failure modes, load-displacement relationships, and shear capacity of the connectors were analyzed. Experimental results demonstrate that the enlarged anchorage effectively enhanced the shear performance of the connectors. Numerical simulations were subsequently carried out on the shear performance of the HEA connectors, and the simulation results were calibrated and validated against experimental data, confirming the reliability of the modeling approach. Further analysis based on stress distribution and contact stress provided additional insight into the structural behavior of HEA connectors. Finally, a parametric study was conducted to evaluate the influence of four key factors including the thickness of LEM and CFS, the strength of CFS, and the anchorage location of the enlarged end. The results revealed that the first three parameters considerably affect shear capacity, whereas the anchorage location of the enlarged end exhibited a very limited effect on shear performance. These findings of this study provide a theoretical foundation for the design and application of floor connection methods in LEM-filled CFS shear wall structures.