Abstract: Discrete element method is used to study probability distribution of tangential forces in granular system with composition disorder.Primary tangential force and secondary tangential force are distinguished and their statistics are analyzed separately.As the rate of defects increases,tangential force distribution transforms from approximate normal distribution to a distribution with two peaks.Finally it becomes a distribution with one peak.Whereas secondary tangential force distribution is always exponential.It shows that force distribution of composition disorder with great defect rate and structural disorder are similar.

Key words: granular matter, DEM simulations, disordered systems, force distribution