搅拌摩擦焊镁合金隔声性能的研究

Research on sound insulation characteristics of the friction stir welding magnesium alloy

伴随搅拌摩擦焊在镁合金上的广泛应用,对其隔声特性研究尤为重要,基于自适应网格技术,对搅拌摩擦焊过程进行数值模拟,为后续声学计算提供约束模态,解决了材料属性难以确定的问题,一定程度上实现了焊接与声学的结合。自行设计和制造了混响箱,用以测量焊接镁合金板的隔声量,弥补了混响室测试小试件的不足。进而使用finite element-statistical energy analysis(FE-SEA)混合法计算焊接件的隔声量,与试验结果进行对比,吻合良好,表明此方法行之有效。通过对比焊接前后镁合金板件的隔声量,发现在吻合低谷区,焊接后板件的隔声有所降低。为了研究焊接参数对隔声的影响,分别改变焊接速度和搅拌头旋转速度,观察隔声量的变化,结果表明,这些参数都需要合理的设置,并非越大或者越小越好。

The friction stir welding（FSW） on magnesium alloy has already been widely used.Therefore,the research on its sound insulation characteristics appears particularly significant.Based on the adaptive meshing technique,the FSW procedure was numerically simulated to provide constraint mode for the next acoustic calculation,which solved the problem of the material properties and achieved a combination of welding and acoustic to some extent.Subsequently,designing and manufacturing a reverberation box to measure transmission loss（TL） of the welded magnesium alloy plate,which could make up the shortage of a reverberation chamber in measuring the little specimen.Based on FE-SEA hybrid method,the method was employed to calculate the TL which was then compared with the experimental one and showed better consistency,prove feasible to predict the TL in FSW on magnesium alloy.Comparisons between the welded magnesium alloy plate TL and the unwelded one could find that TL is reduced after welding.Changing the welding speed and the stir head rotation speed respectively to observing TL in order to study the influence of the welding parameters,which proves that the parameters should be required to set reasonable and neither the bigger nor smaller parameters is better.