بررسي رفتار جذب انرژي لوله هاي دايروي با شيار عرضي در لهيدگي محوري

Energy Absorption Characteristics of Circular Tubes with Circular Circumferential Pattern in Axial Crushing

جاذب انرژي به منظور دريافت انرژي غير مطلوب استفاده مي شود. يكي از پركاربردترين جاذب هاي انرژي لوله هاي جدار نازك مي باشند. ايجاد شيار و يا الگو در جداره لوله به منظور بهبود جذب انرژي انجام مي شود. در اين مقاله ويژگي‌هاي تغيير انرژي جذب شده لوله هاي آلومينيومي داراي الگوي محيطي بررسي و با لوله با جداره صاف به كمك روش المان محدود مقايسه شده است. الگوهاي دايروي محيطي با طول هاي مختلف و همچنين عمق هاي مختلفي در نظر گرفته مي شوند. به كمك شبيه سازي عددي، لهيدگي استاتيكي آنها تحليل مي شود.

Energy absorbents are very common in different industries. As can be inferred, they absorb energy when it is necessary in order to prevent possible damages, those could endanger sensitive components. In this study energy absorb er applicable in an automotive bumper system is investigated. It is focused on thin-walled tubular absorbents in axial crushing mode. In this kind of absorb er, tube’s wall buckles locally and deformation in form of sequential folds holds energy and absorbs counterpart external energy. One method to further control energy absorption is to introduce circumferential patterns on tube’s wall. This pattern can dictate the evolution of folds within crushing distance. Here, the effect of pattern’s parameter, like geometry, wave length and depth on energy absorbing behavior of aluminum thin-walled tubes is studied. Energy absorption in static axial crushing is simulated using Finite Element Method. Different pattern’s geometry, like linear, circular and sinusoidal patterns were generated and results were compared with plain tube, that with no pattern. The effect of introducing patterns on different energy absorption characteristics namely, first force pick, mean crushing force, crushing force efficiency, energy absorbed, specific energy absorbed and crushing mode are explored. Findings show that patterns are very influential on energy absorbing behavior of thin-walled tubes. Results show acceptable combination of pattern’s parameters in each set of pattern’s geometry; even though circular pattern yields more desirable outputs.