柱壳和锥壳结构自由振动特征的数值计算与校验

发布时间：2017-12-31 16:08

本文关键词：柱壳和锥壳结构自由振动特征的数值计算与校验　出处：《声学学报》2017年03期 　论文类型：期刊论文

【摘要】：为了评估柱壳和锥壳结构自由振动特征数值计算的精度,分析不同边界条件、环肋、纵肋以及流体载荷对自由振动特征的影响,计算并校验了典型壳体结构在空气中、浸没以及浸没并充满水情况下的自由振动特征。结果表明,空气中干模态分析在2 kHz内、单面及双面接触水情况下的流固耦合湿模态分析在500 Hz内的计算精度能够控制在10%以内。壳体流固耦合自由振动分析时可以采用实体单元离散也可以采用壳单元离散的方法,前者精度略高,能够有效保证求解收敛的频带范围更宽,但工作量更大。径长比大于0.2时,浸没于水中的自由振动分析可以转换为内部填充水时的自由振动分析,转换时应保证两者流固耦合湿表面积相等,如半浸水和半充满水,能够有效减小计算量;环肋和流体载荷对壳体自由振动特征的影响明显,环肋使柱壳同阶自振频率增加,流体载荷使柱壳同阶自振频率减小且影响幅度更大,两者均会使得柱壳模态振型呈现错序排列;流固耦合效应对无肋柱壳和环肋柱壳自振频率的影响效果相当;柱壳内外有水相对于单面接触水而言,同阶自振频率进一步减小,模态振型基本不变;流体载荷对环肋锥壳的自振频率和模态振型的影响幅度较对环肋柱壳小。
[Abstract]:In order to evaluate the numerical calculation of cylindrical and conical shell structure free vibration characteristics of the precision analysis of ring stiffened with different boundary conditions, and effects of longitudinal ribs and fluid load on the free vibration characteristics, calculation and check the typical shell structure in the air, immersion and immersed and full of free vibration characteristics of water conditions. The results show that the modal analysis within 2 kHz in dry air, single-sided and double-sided solid coupling contact with water under the condition of wet modal analysis calculation accuracy within 500 Hz can be controlled within 10%. The fluid solid coupling analysis of free vibration can be used when the entity unit can also use discrete methods for the discretization of the shell element, the accuracy of the former is slightly higher. Can effectively guarantee the convergence of the frequency range is wider, but a greater workload. The ratio of diameter to length is greater than 0.2, the analysis can be converted to the free vibration analysis of the free vibration of water filled submerged in water, turn Change should guarantee the FSI wet surface area equal to two, such as semi immersion and half filled with water, can effectively reduce the amount of computation; impact of rings and fluid load on the free vibration characteristics of shell, ring stiffened cylindrical shell with the vibration frequency increases, the fluid loading of cylindrical shell with vibration frequency decreases and the impact of a larger, both the cylindrical shell modes show wrong order; the coupling effect of stiffened cylindrical shell and stiffened cylindrical shell vibration frequency influence the effect of a cylindrical shell; inside and outside the water relative to the single contact with water, vibration frequency is further reduced and modal the basic unchanged; affect the rate of fluid loading of ring stiffened conical shell vibration frequency and vibration modal of ring stiffened cylindrical shell.

【作者单位】：舰船综合电力技术国防科技重点实验室(海军工程大学);海军工程大学动力工程学院;水下测控技术重点实验室;海军工程大学电子工程学院;
【基金】：水下测控技术重点实验室基金项目(YS0C261504) 中国博士后科学基金项目(中博基字[2016]16号) 海军工程大学自主立项科研项目(425517 K147) 装备预研基金重点实验室基金项目(6142217050503) 国家自然科学基金项目(51009144)资助
【分类号】：O327
【正文快照】： 31^- ^ 柱壳和锥壳是典型的艇壳结构,其自由振动特性直接关系到艇内机械设备振动和桨轴系统耦合振动所辐射的声学特性。分析壳体结构自由振动特征时,常用的方法有解析法、数值计算方法和模型试验测量。在假定各向运动同步以及轴向和周向模态振型在空间独立的条件下,解析法以轴

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