GBTE stands for gearbox transmission error. GBTE analysis is different from single gear (isolated gear pair) pair transmission error analysis. The single gear pair TE analysis assumes constant torque throughout the mesh, it also assumes constant gear mesh misalignment throughout the mesh and does not consider the influence of other gear mesh. It is also important to note that mesh moment stiffness is not considered in single gear pair TE analysis, where as GBTE does consider. However, these assumptions needed for the analysis of an isolated (single gear pair) gear pair are seen to be invalid in the case of planetary systems because the torque sharing of the planets will cycle with each tooth pass. GBTE Analysis is the ideal tool as it eliminates the inherent assumptions and captures the overall transmission errors caused by all of the loaded gear meshes. It important to note that GBTE tool is not only for planetary gear system, you can also use GBTE tool for non-planetary gear system. For more detailed information you can also go through NVH1 tutorial.
