Forensic Engineering Testing And Analysis Of The Fatigue Failure Of A Hose Clamp

Abstract

Worm-Drive Band Clamps Or Hose Clamps Are Used Commonly Throughout Industry, Such As In Automotive Applications, To Provide A Reliable Seal Against Liquid Leakage Between A Flexible Hose And A Rigid Male Receiver. The Band Clamp Reliability Is Seldom Questioned And The Typical Engineering Concern Is With The Seal Quality Only. However The Current Investigation Shows That Fatigue Failure Modes Can Develop Under Normal And Foreseeable Conditions Of Use That Will Render A Band Clamp Defective. A Fatigue Failure Of A Band Clamp Would At First Seem Remote And Justifiably Neglected By The Design Engineer Due To The Apparent Lack Of High Cyclic Loads. However Analysis Of A Failed Band Clamp Utilized To Secure A Hose Between An Automotive Radiator And Water Pump Together With Testing For Maximum Strain In An Exemplar Band Clamp-Hose System Has Demonstrated That Fatigue Should Be Considered As Part Of The Initial Design Criteria. The High Clamping Load Capability Of The Band Clamp Together With Low Cyclic Variation In The Load Due To Road And Engine Vibrations Can Indeed Lead To A Fatigue Failure Of The Metal Band. The Fatigue Induced Band Clamp Failure In The Case Study Presented Plus The Testing And Analysis Performed On The Exemplar Clamp, Suggest That Long Term Reliability Of Band Clamps Subjected To Severe Service Conditions May Be Compromised Due To Fatigue Loading.