Benchmark of Plate Forming and Weld Distortion Process

2005 ◽  
Vol 128 (3) ◽  
pp. 414-419
Author(s):  
James Gombas
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Cylindrical Shell ◽  
Large Deflection ◽  
Element Analysis ◽  
Manufacturing Simulation ◽  
Simulation Process ◽  
Weld Distortion ◽  
Deflection Theory ◽  
Large Deflection Theory

A circular flat plate with a perforated central region is to be formed by dies into a dome and then welded onto a cylindrical shell. After welding, the dome must be spherical within a narrow tolerance band. This plate forming and welding is simulated using large deflection theory elastic-plastic finite element analysis. The manufacturing assessment is performed so that the dies may be designed to compensate for plate distortions that occur during various stages of manufacturing, including the effects of weld distortion. The manufacturing simulation benchmarks against measurements taken at several manufacturing stages from existing hardware. The manufacturing simulation process can then be used for future applications of similar geometries.

Benchmark of Plate Forming and Weld Distortion Process

2004 ◽  
Author(s):  
James M. Gombas
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Cylindrical Shell ◽  
Large Deflection ◽  
Element Analysis ◽  
Manufacturing Simulation ◽  
Simulation Process ◽  
Weld Distortion ◽  
Deflection Theory ◽  
Large Deflection Theory

A circular flat plate with a perforated central region is to be formed by dies into a dome and then welded onto a cylindrical shell. After welding, the dome must be spherical within a narrow tolerance band. This plate forming and welding is simulated using large deflection theory elastic-plastic finite element analysis. The manufacturing assessment is performed so that the dies may be designed to compensate for plate distortions that occur during various stages of manufacturing, including the effects of weld distortion. The manufacturing simulation benchmarks against measurements taken at several manufacturing stages from existing hardware. The manufacturing simulation process can then be used for future applications of similar geometries.

Predicting the Large Deflection Path of End-Loaded Tapered Cantilever Beams

2000 ◽  
Author(s):  
Matthew B. Parkinson ◽  
Gregory M. Roach ◽  
Larry L. Howell
Keyword(s):  
Mathematical Model ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Euler Equation ◽  
Large Deflection ◽  
Nonlinear Finite Element ◽  
Cantilever Beams ◽  
Element Analysis ◽  
Moments Of Inertia ◽  
Physical Testing

Abstract A simple (quadratic) mathematical model for predicting the deflection path of both non-tapered and continuously tapered cantilever beams loaded with a vertical end force is presented. It is based on the proposition that the path is a function of the ratio of the endpoints’ moments of inertia. The model is valid for both small and large (the tip makes a 70 degree angle with the horizontal) deflections. This was verified through physical testing, comparison to solution of the Bernoulli-Euler equation, and results obtained through nonlinear finite element analysis. Predicted endpoint deflections were found to be accurate within 1.8% of the actual deflection path for moment of inertia ratios varying from 1:1 to 1000:1.

scholarly journals Dynamic instability of a compound nanocomposite shell

2021 ◽  
Vol 27 (5) ◽  
pp. 60-70
Author(s):  
N.H. Sakhno ◽  
◽  
K.V. Avramov ◽  
B.V. Uspensky ◽  
◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Cylindrical Shell ◽  
Supersonic Flow ◽  
Uniform Distribution ◽  
Critical Pressure ◽  
Natural Frequencies ◽  
Dynamic Instability ◽  
Element Analysis

Free oscillations and dynamic instability due to supersonic airflow pressure are investigated in a functional-gradient compound composite conical-cylindrical shell made of a carbon nanotubes-reinforced material. Nanocomposite materials with a linear distribution of the volumetric fraction of nanotubes over the thickness are considered. Extended mixture rule is used to estimate nanocomposite’s mechanical characteristics. A high-order shear deformation theory is used to represent the shell deformation. The assumed-mode technique, along with a Rayleigh-Ritz method, is applied to obtain the equations of the structure motion. To analyze the compound structure dynamics, a new system of piecewise basic functions is suggested. The pressure of a supersonic flow on the shell is obtained by using the piston theory. An example of the dynamic analysis of a nanocomposite conical-cylindrical shell in the supersonic gas flow is considered. The results of its modal analysis using the Rayleigh-Ritz technique are close to the natural frequencies of the shell obtained by finite element analysis. In this case, finite element analysis can only be used for shells made of material with a uniform distribution of nanotubes over the thickness. The dependence of the natural frequencies of a compound shell on the ratio of the lengths of the conical and cylindrical parts is studied. The dependence of the critical pressure of a supersonic flow on the Mach numbers and the type of carbon nanotubes reinforcement is investigated. Shells with a concentration of nanotubes predominantly near the outer and inner surfaces are characterized by higher values of natural frequencies and critical pressure than the shells with a uniform distribution of nanotubes or with a predominant concentration of nanotubes inside the shell.

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