scholarly journals Virtual Reality Interactive Design Utilizing Meshless Stress Re-Analysis

2005 ◽  
Author(s):  
Kurt Chipperfield ◽  
Judy Vance
Keyword(s):  
Virtual Reality ◽  
Stress State ◽  
Interactive Design ◽  
Free Form ◽  
Accurate Approximation ◽  
Original Design ◽  
Accurate Analysis ◽  
Taylor Series Approximation ◽  
Analysis Technique ◽  
Free Form Deformation

Interactive design gives engineers the ability to modify the shape of a part and immediately see the changes in the part’s stress state. Virtual reality techniques are utilized to make the process more intuitive and collaborative. The results of a meshless stress analysis are superimposed on the original design. As the engineer modifies the design using subdivision volume free-form deformation, the stress state for the modified design is computed using a Taylor series approximation. When the designer requests a more accurate analysis, a stress re-analysis technique based on the pre-conditioned conjugate gradient method is used with parallel processing to quickly compute an accurate approximation of the stresses for the new design.

scholarly journals Applying Virtual Reality Techniques to Sensitivity-Based Structural Shape Design

1998 ◽  
Vol 120 (4) ◽  
pp. 612-619 ◽  
Author(s):  
T. P. Yeh ◽  
J. M. Vance
Keyword(s):  
Sensitivity Analysis ◽  
Virtual Reality ◽  
Three Dimensional ◽  
Element Model ◽  
Free Form ◽  
Shape Design ◽  
Connecting Rod ◽  
Structural Shape ◽  
Initial Application ◽  
Free Form Deformation

Virtual reality (VR) provides a design space consisting of three-dimensional computer images where participants can interact with these images using natural human motions in real time. In the field of engineering design, prototyping and design verification have provided the initial application areas for VR. The research presented in this paper takes the scenario one step further by incorporating free-form deformation techniques and sensitivity analysis into the virtual world such that the designer can easily implement analysis-based shape design of a structural system where stress considerations are important. NURBS-based free-form deformation (NFFD) methods and direct manipulation techniques are used as the interface between the VR interaction and the finite element model. Sensitivity analysis is used to allow the designer to change the design model and immediately view the effects without performing a re-analysis. An engine connecting rod is analyzed to demonstrate how virtual reality techniques can be applied to structural shape design.

Virtual Reality Sculpture Using Free-Form Surface Deformation

1997 ◽  
Author(s):  
Todd J. Furlong
Keyword(s):  
Virtual Reality ◽  
Surface Deformation ◽  
Direct Interaction ◽  
Free Form ◽  
State University ◽  
Iowa State University ◽  
Free Form Deformation ◽  
Free Form Surface ◽  
Modes Of Interaction ◽  
Intuitive Manner

Abstract Free-form deformation allows a user to deform surfaces in an intuitive manner that has been compared to sculpting clay (Sederberg and Parry, 1986). This research investigates the use of this deformation technique to create virtual sculpture in the Iowa State University C2, a CAVE™-like apparatus. Emphasis is on intuitive and direct interaction with a surface in order to mold it into whatever shape the user has in mind. An icon-based menu is provided for changing modes of interaction, and a 3D paint tool allows users to add color to their models. Possible applications of this research include virtual art and conceptual or industrial design.

scholarly journals Applying Virtual Reality Techniques to Sensitivity-Based Structural Shape Design

1997 ◽  
Author(s):  
Tsung-Pin Yeh ◽  
Judy M. Vance
Keyword(s):  
Sensitivity Analysis ◽  
Virtual Reality ◽  
Three Dimensional ◽  
Element Model ◽  
Free Form ◽  
Shape Design ◽  
Connecting Rod ◽  
Structural Shape ◽  
Initial Application ◽  
Free Form Deformation

Abstract Virtual reality (VR) provides a design space consisting of three-dimensional computer images where participants can interact with these images using natural human motions in real time. In the field of engineering design, prototyping and design verification have provided the initial application areas for VR. The research presented in this paper takes the scenario one step further by incorporating free-form deformation techniques and sensitivity analysis into the virtual world such that the designer can easily implement analysis-based shape design of a structural system where stress considerations are important. NURBS-based free-form deformation (NFFD) methods and direct manipulation techniques are used as the interface between the VR interaction and the finite element model. Sensitivity analysis is used to allow the designer to change the design model and immediately view the effects without performing a re-analysis. An engine connecting rod is analyzed to demonstrate how virtual reality techniques can be applied to structural shape design.

Airfoil Optimization Using Area-Preserving Free-Form Deformation

2015 ◽  
Author(s):  
Stavros N. Leloudas ◽  
Giorgos A. Strofylas ◽  
Ioannis K. Nikolos
Keyword(s):  
Cross Sectional Area ◽  
Equality Constraint ◽  
Optimization Process ◽  
Free Form ◽  
Sectional Area ◽  
Cross Sectional ◽  
Airfoil Optimization ◽  
Free Form Deformation ◽  
Correction Problem ◽  
Area Preserving

Given the importance of structural integrity of aerodynamic shapes, the necessity of including a cross-sectional area equality constraint among other geometrical and aerodynamic ones arises during the optimization process of an airfoil. In this work an airfoil optimization scheme is presented, based on Area-Preserving Free-Form Deformation (AP FFD), which serves as an alternative technique for the fulfillment of a cross-sectional area equality constraint. The AP FFD is based on the idea of solving an area correction problem, where a minimum possible offset is applied on all free-to-move control points of the FFD lattice, subject to the area preservation constraint. Due to the linearity of the area constraint in each axis, the extraction of an inexpensive closed-form solution to the area preservation problem is possible by using Lagrange Multipliers. A parallel Differential Evolution (DE) algorithm serves as the optimizer, assisted by two Artificial Neural Networks as surrogates. The use of multiple surrogate models, in conjunction with the inexpensive solution to the area correction problem, render the optimization process time efficient. The application of the proposed methodology for wind turbine airfoil optimization demonstrates its applicability and effectiveness.

Shape Optimization by Free-Form Deformation: Existence Results and Numerical Solution for Stokes Flows

2013 ◽  
Vol 60 (3) ◽  
pp. 537-563 ◽  
Author(s):  
Francesco Ballarin ◽  
Andrea Manzoni ◽  
Gianluigi Rozza ◽  
Sandro Salsa
Keyword(s):  
Shape Optimization ◽  
Numerical Solution ◽  
Existence Results ◽  
Free Form ◽  
Stokes Flows ◽  
Free Form Deformation

Fully Free-Form Deformation Features (δ-F4) Incorporating Discontinuities

2004 ◽  
Author(s):  
Vincent Cheutet ◽  
Jean-Philippe Pernot ◽  
Jean-Claude Leon ◽  
Bianca Falcidieno ◽  
Franca Giannini
Keyword(s):  
Surface Deformation ◽  
Geometric Constraints ◽  
Free Form ◽  
Initial Surface ◽  
Cad Systems ◽  
Free Form Deformation ◽  
Deformation Features ◽  
Generate Surface ◽  
Prototype Software ◽  
Free Form Surfaces

To limit low-level manipulations of free-form surfaces, the concept of Fully Free Form Deformation Features (δ-F4) have been introduced. They correspond to shapes obtained by deformation of a surface area according to specified geometric constraints. In our work, we mainly focused on those features aimed at enforcing the visual effect of the so-called character lines, extensively used by designers to specify the shape of an object. Therefore, in the proposed approach, 3D lines are used to drive surface deformation over specified areas. Depending on the wished shape and reflection light effects, the insertion of character lines may generate surface tangency discontinuities. In CAD systems, such kind of discontinuities is generally created by a decomposition of the initial surface into several patches. This process can be tedious and very complex, depending on the shape of the deformation area and the desired surface continuity. Here, a method is proposed to create discontinuities on a surface, using the trimming properties of surfaces. The corresponding deformation features produce the resulting surface in a single modification step and handle simultaneously more constraints than current CAD systems. The principle of the proposed approach is based on arbitrary shaped discontinuities in the parameter domain of the surface to allow the surface exhibiting geometric discontinuities at user-prescribed points or along lines. The proposed approach is illustrated with examples obtained using our prototype software.

Collision handling for free-form deformation embedded surface

2011 ◽  
Vol 5 (4) ◽  
pp. 341 ◽  
Author(s):  
S. Jung ◽  
M. Hong ◽  
M.-H. Choi
Keyword(s):  
Free Form ◽  
Collision Handling ◽  
Free Form Deformation
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