Analysis On The Influence Of The Join Strength And The Fatigue Life Of Clinching With Forming Parameters

More and more severe environment, the increasing depletion of energy and low-cost pursuit have contributed to the development of lightweight while it’s an effective means to solve the above problems. Mainly it uses the present lightweight materials such as aluminum alloy, magnesium alloy and high-strength steel. But the general connection technology of lightweight materials on automobile has certain limitations, for example spot welding can produce thermal deformation and damage the surface of the plate while riveting and bonding costs higher. Therefore in recent years, automobile manufacturers begin to use a new connection technology—clinching.Aluminum alloy Al5052 as the research object, the geometric parameters of mold directly determine the effect of clinched panel parts in the cold stamping process, thus affecting its mechanical properties under three working condition of shear, peel and cross.The geometric parameters of mold mainly include punch and die gap, die boss angle,clinching rate, die section angle and clinching depth H. Therefore, this paper mainly divides into two parts:(1) analysis on the influence of the joining strength of clinching with forming parameters in different working condition(2) analysis on the influence of the fatigue life of clinching with forming parameters in different working condition.Firstly, the forming quality of the sheet structure mainly depends on neck thickness value, interlock value and bottom thickness value. From analysis on the clinching joint effect can be seen in the different die forming parameters of mold, a larger punch and die gap can increase neck thickness value with no-line trend while increase interlock value with line trend. A larger die boss angle, clinching rate, die section angle and clinching depth can decrease neck thickness value while increase interlock value. Clinching depth、clinching rate has an effect on bottom thickness value obviously and the change trend of both is just opposite. Overall, neck thickness value, interlock value and bottom thickness valuefluctuation range is small.Secondly, in the static mechanical strength performance analysis of sheet structure under different die forming parameters, the force change trend of peel and cross is basically consistent. A larger die boss angle can decrease at first then increase then decrease the largest strength of cross and peel. A larger die gap, die section angle and clinching depth can increase at first then decrease then increase the largest strength of cross and peel. A larger clinching rate can increase at first then decrease the largest strength of cross and peel.Clinching depth、clinching rate has an effect on the largest strength of shear obviously.Finally, in the dynamic mechanical strength performance analysis of sheet structure under different die forming parameters,find that a larger die boss angle、clinching rate、die section angle can decrease at first then increase the fatigue damage value of cross and the fatigue damage value of peel and shear has a small influence with different die forming parameters. a larger die boss angle, clinching rate, die section angle can increase at first then decrease the fatigue life of cross and a larger punch and die gap, clinching rate, die section angle can increase at first then decrease the fatigue life of peel while the fatigue resistance of shear is the best in three working conditions.