Sedarage, Bandu Gamini creator Horii, Hideyuki Chairperson Karasudhi, Pisidhi Examination Committee Worsak Kanok-Nukulchai Examination Committee Norwegian Government (NORAD) Scholarship Donor text th Bangkok Asian Institute of Technology 1990 monographic eng

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62 p. Influence of the nonlinear tension-softening curve on the fracture behavior of finite size concrete specimens is discussed by using Boundary Element Method (BEM). A boundary element method program is developed for Dugdale-Barenblatt -type model of bridging zone with nonlinear tension-softening curve to investigate the effect of shape of tension-softening curve on the fracture behavior. Boundary integral equations (BIE) equivalent to original crack problems are presented with a consideration on the treatment of crack boundaries. Wedge loaded specimens and three point bending specimens with different sizes are analyzed with linear and nonlinear tension-softening curves. The results for wedge loaded specimens obtained by the present model are compared with those by an existing model and the experimental results. The maximum loads predicted by the present model for three point bending specimens, are also compared with the experimental results. Along bridging zone which is modelled as a part of crack with stress transmitted by aggregate, the transmitted stress and crack opening displacement (normal stress and normal displacement gap) satisfy a given relationship which is called tension-softening curve. The stress intensity factor at the tip of the bridging zone is assumed to be zero which assures that stress is bounded. With these conditions, boundary integral equations are solved numerically where boundary quantities are approximated by piecewise constant functions. For given specimen geometry, loading condition and bridging zone length, an associated value of load is obtained, together with distributions of transmitted stress and crack opening displacement. In general, the transmitted stress is a nonlinear function of the crack opening displacement. To satisfy this nonlinear relationship, Boundary Element Method (BEM) program is modified with Newton-Rapson's method. A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Engineering and Technology Thesis (M.Eng.) - Asian Institute of Technology, 1990 Concrete Cracking Asian Institute of Technology. http://203.159.5.9/ait-thesis/detail.php?q=B18565 http://203.159.5.9/ait-thesis/detail.php?q=B18565 270798 20260817171655.0