Investigation On Fatigue Damage Of Packaging Products Structure Under Continuous Dynamic Loading

Fatigue failure is a very common phenomenon in aviation, shipbuilding, marine engineering, construction, machinery manufacturing, and other fields. Fatigue is an insidious damage mechanism, seems to have been carried out in secret, and can not be completely avoided. In these fields, the research history of fatigue failure are more than a century, and has formed a complete theoretical system, the possible anti-fatigue design methods has been explored. In the packaging field, fatigue failure can be seen everywhere, but the research on the fatigue failure is still very rare, for the packaging field fatigue study has important practical significance.In this paper, the fatigue properties of the corrugated board structure were discussed by fatigue damage test, fatigue residual strength test and amplitude fatigue test.The object of this research is 02 corrugated boxes without cover, with alternating load applying to them, the relationship of fatigue life and the maximum dynamic load was analyzed. The F-N curve and model of fatigue damage were presented. The curve shows that the structure of corrugated cardboard and metal fatigue life curve is similar and can be described as power function, but different with metal materials, the corrugated board structure does not extend as cracks to a certain scale to cause structural damage, but in the form of structural buckling to fatigue damage.Through the fatigue residual strength experiment, discover the fatigue residual strength of corrugated board structure is greater than the compressive strength of corrugated board structure without vibration, the rise range of compressive strength and the cyclic number of fatigue vibration were not significant correlation, the rise interval of compressive strength was between 3% to 10%. Through the observation and analysis, this paper summarizes there are two main causes of the rise of corrugated cardboard structural fatigue residual strength, one is through the fatigue vibration, the height of the structure's each side goes accordant, the other one is when the structure and the linking piece contact range increases, the restraint increases, so that the constrained system stability improves.Miner criterion is the earliest linear fatigue damage cumulative criterion which is still widely used in engineering practice. Through amplitude fatigue test of corrugated board structure founded that Miner standards was too conservative for corrugated board structure and load order has significant effect on fatigue life.Based on the current transport packaging design method, combining with this research achievements and following the limited life design principles by adopting probability fatigue design method, the fatigue design scheme which is suitable for the packaging engineering was proposed.