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BioHorizons Fatigue Test System

BioHorizons Fatigue Test System. Corp 3 Midterm Concepts Presentation. Team Members. Jonathan Hill John Maddox Allen Lindsay Crichton Neal Chris Howell Felicia Craig Bradley Johnson. Project Overview. General Specification ISO Standards Primary Concept Solid Edge

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BioHorizons Fatigue Test System

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  1. BioHorizons Fatigue Test System Corp 3 Midterm Concepts Presentation

  2. Team Members Jonathan Hill John Maddox Allen Lindsay Crichton Neal Chris Howell Felicia Craig Bradley Johnson

  3. Project Overview • General Specification • ISO Standards • Primary Concept • Solid Edge • Advantages/Disadvantages • Water Bath • Economic Analysis • Secondary Concept • Phase II

  4. Specifications and Constraints • General Constraints • small and light enough to operate on a tabletop • clean and quiet enough to operate indoors at the BioHorizons offices • Able to perform fatigue tests as well as static load tests • Control system and sensors must measure failure load and cycles to failure and discontinue operation at this point • Entire system must be able to be calibrated accurately enough for continuous operation within ISO 14801 specifications and constraints • Economic Constraints • to produce a fatigue testing machine that can be reproduced and used for less than it currently costs to have the dental implants tested from an outside company

  5. ISO Standards • ISO provides more specific specifications and constraints in ISO 14801—Dentistry—Fatigue test for endosseous dental implants • Several of the more pertinent specifiations are covered below, obtained from the ISO document: • The testing machine should be capable of applying the specified load with an error not exceeding ± 5% at maximum load. • The endosseous dental implant shall be clamped such that it makes a 30° ± 1° angle with the loading direction of the testing machine. • The device shall clamp the specimen at a distance 3.0 mm ± 0.1 mm apically from the nominal bone level as specified in the manufacturer’s instruction for use.

  6. ISO Standards (continued) • More constraints and specifications: • The dimensions of the loading member shall be chosen to define a distance l = 11.0 mm ± 0.1 mm from the centre of the hemisphere to the clamping plane. • For endosseous dental implants that include materials in which corrosion fatigue has been reported or is expected to occur…testing shall be carried out in water of Grade 2 according to ISO 3696, in normal saline [.09%]* or in physiologic medium. The fluid and the test specimen shall be kept at 37°C ± 2°C during the testing. • Fatigue testing shall be carried out with a unidirectional load. The load shall vary sinusoidally between a nominal peak value and 10 % of this value. The loading frequency shall be ≤ 15 Hz. Testing in liquid media shall be conducted at frequencies ≤ 2 Hz. *As specified by BioHorizons

  7. Other Applicable ISO Standards • ISO 1099: Metallic materials—Fatigue testing—Axial force controlled method • ISO 1942-1: Dentalvocabulary—Part 1: General and clinical terms • ISO 3696: Water for analytical laboratory use—Specification and test methods • ISO 4965: Axial load fatigue testing machines—Dynamic force calibration—Strain gauge technique • ISO 7500-1: Metallic materials—Verification of static uniaxial testing machines—Part 1: Tension/compression testing machines—Verification and calibration of the force- measuring system

  8. Concept Overview

  9. Different Views

  10. Exploded View Exploded View Temperature Sensor Liquid Bath Container (Pyrex) Frame (steel) Washer (Rubber) Thumb Screw Insert (will be tapped to hold test piece) Container Base Linear Motor/Load Cell Base (steel) Mounting Screws

  11. Advantages • Long life • Excellent precision and reliability • Ease in varying load and frequency • Low maintenance • Easy setup • Small number of parts • Conduct static and fatigue tests without changing setup

  12. Disadvantages • Initial costs are high • Replacement parts would be high • Possible motor cooling may need to be addressed • Different inserts need to be tapped for each implant tested

  13. Water Bath

  14. Major Components • Heating element • Small and compact • Low fluid volume rated • Temperature switch • Small and compact • +-2°C tolerance • Dish • Metal bottom • Glass sides • Water tight • Water level switch • Small and compact • Safely maintain water level

  15. Dish • Metal base • Base for mounting heating components • Able to drain the dish through a ball valve • Glass tube • Forms sides • Able to withstand high temps incase of heating problems • Able to see the test specimen during testing • Washer • Or sealant as of yet to be determined • Seals the base to the glass

  16. Standards • ISO 14801:2003 • 5.4 Testing Environment • testing shall be carried out in water of Grade 2 according to ISO 3696 • fluid and the test specimen shall be kept at 37 °C+2°C or -2 °C

  17. Heating Element • Compact Cartridge-Style Immersion Heater • 1 5/8" long type 316 stainless steel element • Maximum temperature of 100° C • CSA Certified and UL-Registered • Can be fully immerged in saline solution

  18. Temperature switch • Submersible Cartridge Temperature Switch • Operates as a thermostat • 300 series stainless steel outer shell • adjusted between -73° and +315° C • 2” long element • UL-Registered • Search continues to refine this component

  19. Water Level Switch • Vertical-Mount Liquid-Level Switch • Maintain a safe water level for the Immersion heating element • Over all length of 1 7/8“ • Max temperature rating of 105°C • When the fluid level drops too low • cut power to the heating element • turn on a warning light or trigger a system warning in the testing program letting the tester know to add more fluid

  20. Linear Servo Motor • Handles static loading up to 500 lbf. • Handles a cycling load from 0 to 150 lbf. at a rate up to 15 Hz

  21. Load Cell • Piezoelectric sensing cell • Highly repeatable • Fatigue Rated load cell • Low profile to fit easily within machine

  22. Controls • Load cell sends a signal through a DAQ card to LabView • LabView takes the data and depending on the load it will send a signal to the Driver which will in turn increase or decrease the current

  23. Economic Analysis Linear Motor, Cooling Jacket, Controller, and Driver: $19600 Load Cell: $1000 Lab View: $1200 per year Jig Frame and Base: $2000 Computer: $600 Heating Accessories: $300 Cables and Connectors: $200 Total Costs: $25000

  24. Alternative Design

  25. Advantages • Cheap saline bath container • Rotary motor is cheaper than linear motor

  26. Disadvantages • Bearings (maintenance) • Expensive to machine • Small error in load cell reading due to the bearing friction • Angle of applied force will be less reliable • Complicated – many possible places for failure

  27. Phase II-Completed by Dec. • Obtain more quotes on linear motors • Dimension Concept • Stress Analysis • Finalize Concept

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