Chapter6Vehicle EngineeringEnglish for Mechanical Engineering
Chapter 6 Vehicle Engineering English for Mechanical Engineering
CONTENTVehicle Structure Reliability6.1Vehicle System Dynamics and Control6.2Vehicle Vibration and Noise Control6.36.4VehicleDigital Design2
CONTENT 6.1 Vehicle Structure Reliability 6.3 6.2 Vehicle System Dynamics and Control 6.4 Vehicle Digital Design Vehicle Vibration and Noise Control 2
PARTONEVehicle Structure Reliability车辆结构可靠性3
PART ONE Vehicle Structure Reliability 车辆结构可靠性 3
Vehicle Structure ReliabilityReliability Definition Development--- Brief Historyfree ofdefects orsystematicfailuresatthe1960timeitleftthemanufacturer.（出厂无故障）freefromdefectsand systematicfailures at timet=o (whenthey areputintooperation)（出厂无故障）perform therequiredfunctionfailureNOWfreeforastatedtimeinterval（规定时间内无故障）haveafail-safebehaviorincaseofcriticalorcatastrophicfailures.（失效时具有故障保护功能）4
Vehicle Structure Reliability 4 Reliability Definition Development- Brief History 1960 free of defects or systematic failures at the time it left the manufacturer.（出厂无故障） NOW ✓ free from defects and systematic failures at time t = 0 (when they are put into operation) （出厂无故障） ✓ perform the required function failure free for a stated time interval （规定时间内无故障） ✓ have a fail-safe behavior in case of critical or catastrophic failures. （失效时具有故障保护功能）
VehicleStructureReliabilityProbabilityHow to Define Reliability?概率值If n statisticallyidenticaland independent items are put intooperation attimet=O to performagiven missionand v≤n of themaccomplish itsuccessfully,then theratiov/ nis a randomvariable which convergesforincreasingntothetruevalueof thereliability.t=0: v≤nsuccessfullyrandom v / nConverge:Atthetruevalue of thereliability.5
Vehicle Structure Reliability 5 How to Define Reliability ？ Probability 概率值 If n statistically identical and independent items are put into operation at time t = 0 to perform a given mission and v ≤ n of them accomplish it successfully, then the ratio v / n is a random variable which converges for increasing n to the true value of the reliability. random v / n Converge: At the true value of the reliability. t = 0： v ≤ n successfully