[ansys_zhf]

在做一个风机浮运分析，分析关注风机塔筒跟几个支架的作用力，以及塔底与船舶连接处的作用力，我是这么处理的塔底处跟船连接使用刚固（6自由度绑定），塔筒跟支架作用使用fender单元跟塔架接触。问题来了，实际上塔筒是柔体在运输过程中塔筒是会与支架有作用力的，但是所有水动力分析都是刚性分析，塔筒是刚体，那么塔筒就与支架就没有作用力了，我相信大家在做施工计算时肯定遇到类似的问题，请问该如何处理类似塔筒跟支架的连接关系，方便我得出两者的作用力做进一步的强度校核了。

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[wavesurfer]

Sorry, I cannot input chinese in office.

This is a very interesting problem. As I can think of, there are two possible approaches:

1. Use AQWA and ANSYS. In AQWA, model the wind towers and the truss support frames as rigid bodies and get the inertial forces on them. Build the same model in ANSYS but with the elasticity of the structures, then calculate the interaction forces between the frames and towers.

2. If you want to do it completely in AQWA, some approximations need to be made. Assuming the frames are rigid and considering only the elasticity (bending) of the towers. What you can do is to cut each tower into several pieces and each piece is modeled as an individual body. The bodies representing the tower are connected by the Locked Joints. However, before each of the DCON card, use the KCON card to define the actual rotational (bending 4EI/L and torsion GJ/L) stiffness at each cut cross-section of the tower. Between the support frames and towers, you can still define fenders to capture the load. The more pieces you cut the tower, the more accurate results you can get. Even more, you can cut the frames as well.

I don't have direct experience using either of the appoaches. If you decide to do so, please report your outcome to us here. Thanks.

[ansys_zhf]

楼主的第2个方法不错，至少从原理上能说得通，将刚体离散是一种不错的处理方法。多谢 受教。

[wavesurfer]

引用框（ansys_zhf ＠ 03-23-2011 - 15:18）

楼主的第2个方法不错，至少从原理上能说得通，将刚体离散是一种不错的处理方法。多谢 受教。

第一种方法在AQWA中虽然没有考虑风筒的柔性和支架的支撑（与支架无耦合），但是我猜想求出来的最大水平加速度应该还是跟考虑了这些因素（与支架有耦合）的情况差不多的。当在ANSYS中求解的时候，风筒弹性和支架支撑都可以模拟了；而加速度可以作为荷载施加到风筒上。不知这样理解还有什么疏漏？要是两种方法都能做，然后比较一下结果就好了。

[mcdowell]

引用框（wavesurfer ＠ 03-23-2011 - 20:53）

引用框（ansys_zhf ＠ 03-23-2011 - 15:18）

楼主的第2个方法不错，至少从原理上能说得通，将刚体离散是一种不错的处理方法。多谢 受教。

第一种方法在AQWA中虽然没有考虑风筒的柔性和支架的支撑（与支架无耦合），但是我猜想求出来的最大水平加速度应该还是跟考虑了这些因素（与支架有耦合）的情况差不多的。当在ANSYS中求解的时候，风筒弹性和支架支撑都可以模拟了；而加速度可以作为荷载施加到风筒上。不知这样理解还有什么疏漏？要是两种方法都能做，然后比较一下结果就好了。

第一种方法更靠谱，质量阵定了，刚性柔性对运动计算没影响。得到运动用有限元计算，塔和支架变形是协调的。
如果按楼主思路，用第二种方法，平台或船的每个构件都要离散了。
不过第二种方法也很有研究价值，可简化结构模型。

[xfan]

如果你考虑用其它工具也许还有别的计算方法。

[wavesurfer]

引用框（xfan ＠ 04-08-2011 - 16:57）

如果你考虑用其它工具也许还有别的计算方法。

Can you please explain in a little bit more detail? This is an interesting topic. I think many people want to know.

[ansys_zhf]

有没有既可以考虑水动力学载荷又可以将结构当成柔体计算的工具？

[wavesurfer]

引用框（ansys_zhf ＠ 04-15-2011 - 16:08）

有没有既可以考虑水动力学载荷又可以将结构当成柔体计算的工具？

As I know of, the only commercial software for this is WAMIT. You can use generalized modes to handle the structural elasticity. But even figuring out how to use generalized mode is very challenging.

As for research, the topic is called hydroelasticity. I think BV is the world lead in this area.

[Striking]

引用框（ansys_zhf ＠ 04-15-2011 - 15:08）

有没有既可以考虑水动力学载荷又可以将结构当成柔体计算的工具？

Sorry, I can only input English in the office.
Maybe you can try this in OrcaFlex. But before doing this, you should get the hydrodynamics of the vessel first, noted the hydrodynamic model should contain vessel only.

[wavesurfer]

引用框（Striking ＠ 04-18-2011 - 19:32）

引用框（ansys_zhf ＠ 04-15-2011 - 15:08）

有没有既可以考虑水动力学载荷又可以将结构当成柔体计算的工具？

Sorry, I can only input English in the office.
Maybe you can try this in OrcaFlex. But before doing this, you should get the hydrodynamics of the vessel first, noted the hydrodynamic model should contain vessel only.

我估计你是指可以把风机塔模拟成类似于锚线的线单元。然后在锚线（风机塔）的某个中间结点设置与支撑架的连接。不过，这样的话风机塔的柔性并没有反馈到水动力系数里。

[ansys_zhf]

我现在的做法是将架子和风机塔筒的六自由度加速度极限值提取出来然后再ansys中建模，将这些惯性加速度加上，使用惯性释放进行强度计算，不知流程上可否？