Journal of Asian Scientific Research 2(11):673-679 673 NUMERICAL MODELING OF COMPOSITE BEHAVIOUR OF GROUPED STUDS Md. Khasro Miah 1 Akinori Nakajima 2 Ahsanul Kabir 3 ABSTRACT The aim of this study is to compare the numerical model of grouped stud behavior with the experimental results to validate the model under pulsating load. To this end, a numerical model is developed to estimate the static behavior of studs in grouped arrangement, which is often used in the composite structures. The precision of the numerical evaluation mostly depends on the appropriate modeling of shear force transmission from the stud shank to surrounding concrete. This is achieved by employing one-dimensional nonlinear bearing springs and the characteristic responses are estimated from trial and error method. Key Words: Grouped studs, numerical analysis, nonlinear FEA, bearing force, slip, base strain INTRODUCTION In recent years, a number of multiple span bridges are designed with more emphasis to reduce the construction cost and labour. Accordingly, the continuous composite girder bridges with two main girders are frequently constructed to satisfy the demand. Conventionally, headed studs as the shear connectors are arranged uniformly on the top flange of the girder. Frequently, prestressed concrete slabs have been adopted as deck slab in the composite girder bridge construction. The prestressing along the longitudinal direction of the concrete slab transfers large extra stress in the steel girder simultaneously by the conventional jack up-down method. The extra stress is unnecessarily confined both in the concrete slab and steel girder. On the other hand, the grouped stud arrangement (Shim et al., 2004) technique can be employed effectively for prestressing across the 1 Prof., Dept of Civil Engineering, Dhaka Univ. of Engg. and Tech., Gazipur, Bangladesh E-mail: mkhasro@duet.ac.bd ;mkhasro@gmail.com 2 Prof., Dept. of Civil Engg., Graduate School of Engg., Utsunomiya University, 7-1-2 Yoto, Utsunomiya, Japan 3 Prof., Dept. of Civil Engg., Bangladesh Univ. of Engg. and Tech., Dhaka, Bangladesh Journal of Asian Scientific Research journal homepage: http://aessweb.com/journal-detail.php?id=5003