Dr. Paul Langlois

Dr. Paul Langlois is the CAE products development department manager at SMT. Having worked for SMT for 10 years, he has extensive knowledge of transmission analysis methods and their software implementation. He manages the development of SMT's software products and is a main contributor to many aspects of SMT's technical software development. As a member of the BSI MCE/005 committee, Langlois contributes to ISO standards development for gears.  (Bio last updated 2018-02-05 Contact Randy Stott, Managing Editor, with changes.)

Articles by Paul Langlois

  • Tooth Contact Analysis - Off Line of Action Contact and Polymer Gears (September/October 2017)
    The aim of the study was to apply such a specialized tooth contact analysis method, well-used within the steel gear community, to a polymer gear application to assess what modifications need be made to these models for them to be applicable to polymer gears.
  • Finite Element Analysis of Tooth Flank Fracture Using Boundary Conditions from LTCA (September/October 2016)
    This paper demonstrates an application of the tooth interior fatigue fracture (TIFF) analysis method, as implemented in SMT's MASTA software, in which loaded tooth contact analysis (LTCA) results from a specialized 3-D contact model have been utilized to determine the load boundary conditions for analysis of tooth flank fracture (TFF).
  • Hybrid Hertzian and FE-Based Helical Gear-Loaded Tooth Contact Analysis and Comparison with FE (July 2016)
    Gear-loaded tooth contact analysis is an important tool for the design and analysis of gear performance within transmission and driveline systems. Methods for the calculation of tooth contact conditions have been discussed in the literature for many years. It's possible the method you've been using is underestimating transmission error in helical gears. Here's why.
  • Noise Reduction in an EV Hub Drive Using a Full Test and Simulation Methodology (May 2016)
    With the ongoing push towards electric vehicles (EVs), there is likely to be increasing focus on the noise impact of the gearing required for the transmission of power from the (high-speed) electric motor to the road. Understanding automotive noise, vibration and harshness (NVH) and methodologies for total in-vehicle noise presupposes relatively large, internal combustion (IC) contributions, compared to gear noise. Further, it may be advantageous to run the electric motors at significantly higher rotational speed than conventional automotive IC engines, sending geartrains into yet higher speed ranges. Thus the move to EV or hybrid electric vehicles (HEVs) places greater or different demands on geartrain noise. This work combines both a traditional NVH approach (in-vehicle and rig noise, waterfall plots, Campbell diagrams and Fourier analysis) - with highly detailed transmission error measurement and simulation of the complete drivetrain - to fully understand noise sources within an EV hub drive. A detailed methodology is presented, combining both a full series of tests and advanced simulation to troubleshoot and optimize an EV hub drive for noise reduction.
  • The Importance of Integrated Software Solutions in Troubleshooting Gear Whine (May 2015)
    NVH — noise, vibration and harshness — is a key issue in the design and development of modern transmission and driveline systems.