Saba Metallurgical and Plant Engineering Services, LLC

       

                      

      SpotLight:  A medical client contacted SMPES, LLC, to help evaluate a change in thread pitch in their spinal fixation device.  They wished to optimize the design to help minimize the potential for cross-threaded by reducing the frictional forces during torquing.  The desired outcome was to determine the new torque rating and axial locking force of the device and percent reduction in torquing frictional forces.  SMPES, LLC used mechanical event simulation in conjuction with surface-to-surface contact to turn the set screw in the screw head.  A modified limit load analysis technique was used to determine the maximum amount of torque the device could withstand.  The torque is found at the last converged time step from the final torque applied to the allen wrench (not shown).  The force used to overcome frictional forces is calculated by summing up the tangential reaction forces at the surface-to-surface threaded contact areas.  Axial locking forces are calculated by summing up axial (vertical) reactions forces on the same surfaces.

      Finite Element Analysis

      Failure Analysis

      Fitness-For-Service

      SPEP
      SMPES, LLC Services
      Linear-Elastic FEA Mechanical Event Simulation Tank & Pressure Vessel Design
      Non-Linear "Limit Load" FEA Computation Fluid Dynamics Failure Analysis & Lab Services
      Non-Linear "Plastic Collapse FEA Strucutral Dynamics Loss Investigation
      Coupled Fluid-Thermal Analysis API 579 FFS Level 2 & 3 Corrosion & Material Selection

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      Recent SMPES News and Events

      dia_gray.gif   Provided "Lunch-and-Learn" Training on API 579      Fitness-For-Service Basics at Total Petrochemicals and      Valero Refinery.

      dia_gray.gif   Principal Engineer, Brent Saba, PE-ME/MT, presented      at local ASME chapter on Finite Element Analysis      Applications in API 579 Fitness-For-Service      Evaluations.

      dia_gray.gif   Medical spinal implant work by SMPES, LLC, featured      in November 2007 Medical Design Magazine article      "Simulating Stresses in Stints, Tension in Tissue".

      dia_gray.gif  SMPES, LLC appears in Algor's inside cover full page      ad in August 2007 issue of Mechanical Engineering      magazine.

      Recent Completed Projects

       dia_gray.gif  Evaluation of thermal stresses of a by-pass mixing tee in      a refinery, using combined CFD, transient and steady-      state thermal analysis, and linear elastic stress analysis.

       dia_gray.gif  Redesign of a reactor cooling baffle in a chemical plant      using linear elastic FEA and modal natural frequency.

       dia_gray.gif Re-Rate of several vessels and heat exchangers using      PV-Elite software at two chemical plants.

       dia_gray.gif  Evaluted and optimized complete Peek VBR product       line of a start-up medical firm.

       dia_gray.gif  Performed API 579 FFS evaluation and de-rate for a       vacuum induced distored tank shell at a chemical plant.

       dia_gray.gif  Completed an intermediate stage evaluation of a       medical fixation device using mechanical event       simulation and multiple surface-to-surface contacts.

                           Saba Metallurgical & Plant Engineering Service, LLC.  •  Baton Rouge, LA 70820  •  225-405-4015