1. Finite Element Analysis Portfolio
Tianyu Li
Tell: (540) 315-2730
Email: lty1990@vt.edu
tlicareer2016@gmail.com
In this Portfolio, I briefly present the FEA for the problems of composite pipe buckling,
composite stiffened plate, composite airfoil structure and composite ship hull. The large
deformation and finite strain are both considered. The elastic and plastic materials are
both analyzed. The contact algorithm is also included for some problems. The impact
problem is also involved.

2. 1. Composite pipe buckling analysis
Purpose: The pipe buckling problem is aimed to analyze the imperfect pipe structure’s
unstable deformation (buckling) under water pressure. The multi-layer composite pipes
are analyzed.
1.1 2-D multi-layer pipe collapse
The critical buckling pressure is analyzed. The post buckling mode is shown in the figure
below. In this figure, the 2-layer composite pipe is collapsed under water pressure.
1.2 3-D pipe buckling propagation
After the pipe is collapsed, the unstable deformation will propagate along the pipeline, as
the two figures below show. The contact between internal surface of the pipeline will be
initiated. The whole pipeline will be damaged. This is called buckling propagation.

3. 1.3 3-D pipe buckling crossover
In order to stop the unstable deformation, the local enhance is added to the pipeline and
we analyze the critical pressure that the buckling deformation will cross over the local
enhance.

4. 1.4 stiffened pipe buckling
The stiffened pipe is more practical. In this kind of pipe structure, the pipe is reinforced
by ribs.
Local enhance

5. 1.5 curved pipe buckling
To make the analysis of pipe buckling more general, the curved pipe is also analyzed. In
this case, the pipe structure’s axial line can be defined as arbitrary space curves.

6. 1.6 Impact analysis between anchor and pipe
The anchor is given an initial speed and it impacts the pipe, causing a local dent on the
pipe. The displacement of the pipe is shown in the figures below.

7. The undeformed pipe and deformed pipe cross-section is shown in the figure below.

8. 2. Stiffened plate analysis
Purpose: the stiffened plate structure is analyzed under pressure. The stiffener can be
defined as arbitrary shapes. A very large deformation occurs in this analysis. The stiffener
will deform with the plate and reinforce the plate to increase the strength of the plate.
2.1 parabolic stiffener
The stiffener is a parabolic as shown below:
Under water pressure, the deflection of the stiffened plate will be deformed as the figure
below shows. In this figure, the deflection is presented.
stiffener

9. 2.2 circle stiffener
The stiffener’s shape is a circle in this case. The deflection under water pressure is shown
in figure below.
2.3 oval stiffener
In this case, the stiffener is an oval. The deformation under water pressure is shown in
figure below.

10. 2.4 arbitrary stiffener
In this case, the stiffener’s shape is defined arbitrarily, as shown below.
The deformation under water pressure is shown in figure below.

11. 3. Composite airfoil
Purpose: the multi-layer stiffened airfoil structure is analyzed. The airfoil is reinforced by
ribs and the airfoil shell is multi-layered. The pressure is applied on the outer surface.

12. The multi-layer airfoil will be collapsed under the pressure, as the figure below shows. In
this figure, we only present a slice of the undeformed and deformed airfoil.

13. 4. Ship hull
Purpose: the ship hull structure under water pressure is analyzed. The ship hull is
governed by Wigley ship hull formulas. The water pressure is applied on the outer surface
of the ship hull. The large deformation analysis is included. For the deformation under
water pressure, it is shown in the figure below.
The stiffened ship hull structure is analyzed. The ribs is also added to the ship hull. The
ribs will increase the strength of the ship hull structure. For the ship hull with ribs, the
deformation will be: