Generation of Computational 3D Models of Human Bones Based on STL Data and CAD Software Packages

This paper presents three methods of converting complex 3D models of STL type into solid models. For converting the STL models, specific approximation functions from CATIA and Creo Parametric software were used as well as 3D solid modeling methods that used sketches drawn for sections of the specific analyzed model. This conversion is required to get a solid 3D model that can be used for finite element analysis and to be processed using Boolean functions in specific CAD programs. This paper also presents a study of the effectiveness of FEA in respect to the time required for the analysis of each converted model. The analyzed STL files contain data obtained by computer tomography and are the 3D models of the human orthopedic system: the left zygomatic bone and upper part of the right femur. The presented conversion methods can be used by design engineers both in medical applications (where the complexity of forms is well known) for the design of implants and for industrial applications for reverse engineering.

Simulation of mode-locking phenomena in a complex nonlinear rotor system using 3D solid finite elements

The most common simulation approach in rotor dynamics is based on beam models. Usually, these models are very compact and come at low computational costs. However, they are afflicted with a number of limitations, making them insufficient for the analysis of more complex rotor systems, which require 3D solid modeling. General purpose FEM codes offer full 3D solid modeling capabilities, but the question still remains, whether they are capable of correctly taking into account all the effects that arise from rotation. This paper provides an example of a complex, highly nonlinear rotor system, which cannot be simulated or even modeled accurately by using beam elements, but rather requires 3D solid modeling. ABAQUS is used-as a representative example for a general purpose FEM code-to build up an appropriate model. By doing so, the paper addresses the question, whether a general purpose FEM code is able to cover the necessary rotor dynamic effects. The model which is derived here takes into account nonlinear stiffness behavior, and includes contact between different components of a rotor assembly. The objective is to simulate a run-up through a bending resonance, using direct time integration. The simulation results are compared with experiments, showing good consistency. During the crossing of the critical speed due to the bending resonance, mode-locking can be observed in the experiment and is well represented by the simulation model.

Motor Rotor Unit Composite Die Design and WEDM Programming of Stamping Dies (Convex-Concave Mould)

This paper introduces motor rotor blanking die design process through specific terms of the process of stamping all. Mould design process is for structural analysis and process analysis of the parts diagram, based on it to determine the technology methods, select the structure of the mould, and make a necessary calculation to determine stock layout and the size of the work part. And choose a suitable punching machine. Finally, choose the parts from the manual of mould.This design also includes the use of AutoCAD software mapping die assembly and major parts map using UG and Pro/E software for 3D solid modeling and animation design simulation process. In addition, the punch and die processing choose WEDM and Programming. So consider the structural design of WEDM of the specific methods to avoid the conflict between design and processing, and guarantee the production reasonable.