Phillippi’s research encompasses methods to determine the actual load distribution in multi-column bridge and building structures through the use of 3D non-linear programs, and simplified analytically-based fiber models that use basic mechanics of materials. Current research has created concrete models that use stiffnesses of variably axially and laterally loaded columns to ascertain the axial and lateral shear distribution in bridges and buildings, which may then be used to determine the state of stress and/or strain of various column components for design or analysis.
His other research involves the use of analytical-based models to determine the axial stress-strain relation and evaluation of transverse and jacket hoop strain levels around concrete columns wrapped with carbon fiber reinforced polymer (CFRP) jackets.
Phillippi authored or coauthored peer-refereed journal articles with topics that included the following: simplified two-column analytically-based fiber model; free fall of self-consolidating concrete in walls three meters high; shear loading in two-column bridge bents; capacity assessment of v-shaped two columns bridge bents; and analytical model for FRP-jacketed square concrete columns in axial compression. He also authored or coauthored peer-refereed conferences papers with topics that included the use of mechanical couplers in concrete columns and an analytical model for predicting CFRP square concrete column jacket strains. Invited speaker topics included the design of timber structures with sawn and engineered wood members as well as wood frame design for residential and small commercial buildings. Seminar topics have included shear distribution in two-column bridge bents, seismic design of structures, seismic shear distribution to vertical shear resisting elements with rigid diaphragms, and diaphragms – flexible and rigid design.
