Abstract
M.Tech. (Mechanical Engineering)
This dissertation reports on the development of unreinforced and reinforced (with 3 wye
branch piece reinforcements) T-section experimental prototypes that were used to validate
numerical models (using 2D & 3D Finite Element Method (FEM)). The design of 3 wye
branch piece reinforcements according to the American Water Works Association (AWWA)
M11 method is accomplished by interpolating the reinforcement profiles from graphs. The
methodology used to generate these graphs are not communicated. Rather, more emphasis is
placed on the design of the reinforcement rather than showing the optimized performance of
the pipe due to the reinforcement. Upon introducing a hole in the barrel pipe for insertion of
the branch pipe, there are changes in local geometrical parameters and hence operational
conditions are significant to the structural and mechanical performance of the T-section pipe.
Pipe profiling severely compromises the localized performance of the T-section pipe
especially at the junction points. The main objective was to develop optimized branched piece
reinforcement profiles that are less conservative when compared to the AWWA technique
without compromising on the performance of the T-section pipe. FEM analysis executed for
both the reinforced and unreinforced T-section pipes provided a cost effective tool in
identifying and suppressing all prevalent detrimental factors when generating the most
optimal profile. Experimental tests on one-to-one scale specimens were carried out by
mounting strain gauges on the reinforced and unreinforced T-section pipes which captured
induced strains as the pressure was gradually increased to the point of bursting. Data was
recorded accordingly. The pipe burst at the radial junction and area of incidents were
consistent with the FEM model predictions, that is, the zone requiring reinforcing. The data
from the experimental prototypes and numerical models correlated with a great degree of
accuracy. Viable solutions to branched piece reinforcements were generated based on
validated numerical models. Optimized branched piece reinforcements developed from
numerical models are safe for use in pipeline infrastructure.