Achieve of Torpedo Shell Parameter Model Based on Secondary Development of UG

Torpedo shell Modeling is a very important part in the design process. However, the traditional method of torpedo shell modeling is only the GUI of CAD drawing software. If there is change in individual parameters, designers have to start again from scratch. Such method will waste of resources. This paper set up the torpedo shell parametric design process with secondary development language UG / Open API, and user-oriented menu creation tool UG / Open UIStyler of UG,which is a three-dimensional modeling software, So that designers can be directly obtained three-dimensional model of the torpedo shell needing to enter the necessary design parameters. Meanwhile the designers can save design resources, and it helps optimize the latter part of the torpedo shell design.

The Onset of Plastic Yielding in a Spherical Shell Compressed by a Rigid Flat

The onset of plastic yielding in a spherical shell loaded by a rigid flat is analyzed using finite element analysis. The effect of spherical shell geometry and material properties on the critical normal load, critical interference, and critical contact area, at the onset of plastic yielding, is investigated and the location where plastic yielding first occurs is determined. A universal dimensionless shell parameter, which controls the behavior of the spherical shell, is identified. An empirical relation is found for the load-interference behavior of the spherical shell prior to its plastic yielding. A limiting value of the dimensionless shell parameter is identified above which the shell behaves like a solid sphere.

The Effect of Contact Conditions on the Onset of Plastic Yielding in a Spherical Shell Compressed by a Rigid Flat

The effect of contact conditions on yield inception of a spherical shell compressed by a rigid flat is studied using finite element analysis. A wide range of material properties and shell thickness values, corresponding to the dimensionless shell parameter, were studied. This work provides the critical load ratio as a function of the shell parameter for different values of the Poisson’s ratio under both slip and stick contact condition. At small values of the Poisson’s ratio the behavior in stick is very different from that in slip. At high values of the Poisson’s ratio the yield inception in stick and slip is similar.

Numerical Analysis of a Spherical Shell Compressed by a Rigid Flat

The elastic-plastic contact between a spherical shell and a rigid flat is analyzed using finite element analysis. The effect of spherical shell geometry and material properties on the onset of plastic deformation is determined by finding the critical normal load and the critical interference which correspond to the onset of plastic yielding. The location of initial plastic deformation is identified as a function of material properties and spherical shell geometry. This work provides the dimensionless critical load as a function of the shell parameter λ = (t/R)*(E/Y), where t, R, E and Y are the spherical shell thickness, radius, Young’s modulus and yield strength, respectively. The numerical results are compared with the solid sphere model based on Hertz’s contact theory and classical shell theory in the elastic regime. The behavior of a spherical shell contacting a rigid flat plate is a strong function of the shell parameter λ.