Nonclassical Models of the Theory of Plates and Shells

An analysis based on the first kind of Lagranges equations was presented for investigating the vibration and acoustic radiation of underwater finite cylindrical shell with interior plate under multiple excitations. The strain energy and kinetic energy of cylinder and plate were gained by the theory of plates and shells, and the potential energy of excitation and fluid loading was found based on acoustic-vibration coupling, and the connection conditions of plate and cylinder were expressed by Lagrange multipliers, then the vibro-acoustic equations of finite cylinder with interior plate under shafting excitation were established. The influences of excitations and plates position to the vibro-acoustic characteristics were studied by the equations. The results show that the frequency components of plate-shell structure are more complex. For the double excitations on plate, the distance between excitations is larger, the average velocity and sound radiation power are lower, while the radiation efficiency is larger. The modeling and analytical methods adopted in this paper are also available for more complex composite structure.

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A simplified method for calculating the stress of a large storage tank wall

Proceedings of the Institution of Mechanical Engineers Part E Journal of Process Mechanical Engineering ◽

10.1243/09544089jpme125 ◽

2007 ◽

Vol 221 (3) ◽

pp. 119-127 ◽

Cited By ~ 6

Author(s):

Z. P. Chen ◽

Y. Y. Duan ◽

J. M. Shen ◽

J. L. Jiang

Keyword(s):

Storage Tank ◽

Stress Test ◽

Bottom Plate ◽

Tank Wall ◽

Measured Stress ◽

Simplified Method ◽

Calculation Results ◽

Theory Of Plates ◽

Plates And Shells ◽

Simplified Calculation

With consideration of the influences from the constraint reaction of tank bottom plate to each shell course, a simplified long-short shell method was proposed to calculate the stress of a large storage tank wall. The first shell course was regarded as a short cylindrical shell while all the others as long cylindrical shells, and the analytic solution equations of shell stress were achieved by theory of plates and shells. With resistance stress-strain method, a field stress test was done on a 15x104 m3 floating-roof oil tank during its water filling test, and the measured stress data are in good agreement with the calculation results obtained by this simplified calculation method for shell stress. Therefore, the simplified method can be adopted to calculate the shell stress of large storage tanks accurately.

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Modeling and Optimization of Bidirectional Clamping Forces in Drilling of Stacked Aluminum Alloy Plates

Materials ◽

10.3390/ma13122866 ◽

2020 ◽

Vol 13 (12) ◽

pp. 2866

Author(s):

Jintong Liu ◽

Anan Zhao ◽

Piao Wan ◽

Huiyue Dong ◽

Yunbo Bi

Keyword(s):

Mathematical Model ◽

Finite Element ◽

Aluminum Alloy ◽

Clamping Force ◽

Practical Application ◽

Element Simulation ◽

Theory Of Plates ◽

Plates And Shells ◽

The Mathematical Model ◽

The Relationship

Interlayer burrs formation during drilling of stacked plates is a common problem in the field of aircraft assembly. Burrs elimination requires extra deburring operations which is time-consuming and costly. An effective way to inhibit interlayer burrs is to reduce the interlayer gap by preloading clamping force. In this paper, based on the theory of plates and shells, a mathematical model of interlayer gap with bidirectional clamping forces was established. The relationship between the upper and lower clamping forces was investigated when the interlayer gap reaches zero. The optimization of the bidirectional clamping forces was performed to reduce the degree and non-uniformity of the deflections of the stacked plates. Then, the finite element simulation was conducted to verify the mathematical model. Finally, drilling experiments were carried out on 2024-T3 aluminum alloy stacked plates based on the dual-machine-based automatic drilling and riveting system. The experimental results show that the optimized bidirectional clamping forces can significantly reduce the burr heights. The work in this paper enables us to understand the effect of bidirectional clamping forces on the interlayer gap and paves the way for the practical application.

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