a PhD thesis in the College of Engineering at the University of Basrah discussing (conductor resistance in the new composite system of iron and concrete) The thesis presented by the student Hussein Rahim dealt with the necessity of using the shear stirrups of the reinforced concrete beam as shear connectors when passing through Drilled holes in the T-shaped inverted section iron grid. The program of this study consists of conducting experimental work, numerical analysis and comparison of the results. The experimental work consists of testing a new arrangement of payment samples proposed for this purpose. What has been manufactured and tested A total of fifty-six thrust samples to verify the effect of several variables on the shear strength and sliding capacity of the shear connector. The variables studied in this experimental investigation are the dimensions of the sample (length and width), the diameter of the stirrups (shear conductor), the number of conductors per sample, the strength of the concrete, and the type (size) T section, and sample shape. For all samples, Two diameters of iron bars to serve as the shear connector. Two sizes of T-sections, 30 MPa and 42 MPa concrete, were used in this study. Numerical analysis was performed by creating a 3D finite element model using Student Edition ANSYS finite element program 21 to simulate the structural behavior of a new iron composite system and concrete with innovative shear connectors. The objective of the thesis is to investigate the strength and behavior of a new shear conductor in a new steel-concrete composite system. The thesis concluded that the resistance of the conductor in the experimental test is greatly affected by some test variables. Conductor resistance decreases with increasing number of conductors in the samples and increases with increasing shear conductor diameter, sample width and resistivity concrete. Other variables have little effect on the ultimate shear strength of a conductor The general behavior of the new shear connectors showed high stiffness in the initial stages of loading The relationship between load and resulting slip is approximately linear.