A Structural Model for Molded Thermoplastic Ankle-Foot Orthoses

1987 ◽  
Vol 109 (4) ◽  
pp. 305-310 ◽  
Author(s):  
D. J. Leone
Keyword(s):  
Theoretical Model ◽  
Computer Aided Design ◽  
Structural Model ◽  
Structural Response ◽  
Leaf Spring ◽  
Simple Theoretical Model ◽  
Small Deflection ◽  
Predicted Values ◽  
Deflection Theory ◽  
Aided Design

The structural response of a posterior leaf spring, ankle-foot orthosis (AFO) was studied both experimentally and with a simple theoretical model. The theoretical model, which was compared with other analytical solutions and experimental data, predicted the bending and twisting of the AFO due to unit loads. The simple theoretical model utilized beam equations and small deflection theory. Excellent agreement between test and predicted values was achieved, indicating that the simple theoretical model, which was relatively easy to implement computationally, could serve as the major component of a computer-aided design program.

Tailor-Made Plate Design and Manufacturing System for Treating Bone Fractures in Small Animals

2013 ◽  
Vol 17 (4) ◽  
pp. 588-597 ◽  
Author(s):  
Akio Doi ◽  
◽  
Hiroki Takahashi ◽  
Bunei Syuto ◽  
Masaaki Katayama ◽  
...  
Keyword(s):  
Computer Aided Design ◽  
Structural Model ◽  
Bone Fractures ◽  
Triangular Mesh ◽  
Small Animals ◽  
Veterinary Clinic ◽  
Cad System ◽  
Computed Tomography Images ◽  
Plate Design ◽  
Aided Design

We propose the use of a computer-aided design (CAD) system for treating bone fractures in small animals. During surgical planning, the veterinarian sketches a simple plate by referring to computed tomography images. A CAD operator then uses polygonal approximation (triangulation) of the surface of the bone region to model the plate. After the approximated shape is imported into the CAD system as a triangular mesh, a detailed design of the plate is prepared by referring to the abovementioned sketch. The plate can be designed to match the bone surface since the plate surface follows the curvature of the surface of the exported triangular mesh. The bone shape and the plate are eventually converted into polygons, and a structural model identical to the fractured part of the bone can be reproduced using a 3D printer, which allows for alignment to be performed at full scale. In this study, we examine the applicability of the proposed system by designing the most appropriately shaped plates for bone fracture therapy for small dogs brought to a veterinary clinic for treatment.

Structural Modeling of Undersea Cables

1989 ◽  
Vol 111 (4) ◽  
pp. 323-330 ◽  
Author(s):  
R. H. Knapp
Keyword(s):  
Material Properties ◽  
Computer Aided Design ◽  
Structural Model ◽  
Computer Code ◽  
Internal Stresses ◽  
Complex Geometries ◽  
Design Program ◽  
Undersea Cables ◽  
Aided Design ◽  
Nonlinearly Elastic

A structural model for undersea cables is described. This model has been implemented in a computer-aided design program with the capability to determine cable deformations and internal stresses in response to applied loads including tension, twist, bending, pressure and enforced displacements. Complex geometries and nonlinearly elastic material properties can also be treated. Results of a comprehensive series of physical cable tests to validate the computer code are reported.

Pneumatic Rupture of a Brittle Pipe: The Depressurization Transient Adjacent to the Ruptured Zone

1981 ◽  
Vol 103 (3) ◽  
pp. 287-293 ◽  
Author(s):  
M. R. Baum ◽  
M. J. H. Elston
Keyword(s):  
Theoretical Model ◽  
Rupture Zone ◽  
Bursting Pressure ◽  
Pressure Transient ◽  
Adjacent Section ◽  
Comparison With Experiment ◽  
Simple Theoretical Model ◽  
Wide Range ◽  
Predicted Values

A simple theoretical model is developed to predict the pressure transient within a gas-pressurized pipe when an adjacent section shatters into many fragments. Comparison with experiment shows that the model correctly predicts the general form of the transient over a wide range of bursting pressure and rupture zone lengths, though the measured initial depressurization rates all fall below the predicted values.

Integration of Geometry and Analysis for Vehicle System Applications: Continuum-Based Leaf Spring and Tire Assembly

2015 ◽  
Vol 11 (3) ◽  
Author(s):  
Zuqing Yu ◽  
Yiguan Liu ◽  
Brian Tinsley ◽  
Ahmed A. Shabana
Keyword(s):  
Computer Aided Design ◽  
Contact Forces ◽  
Leaf Spring ◽  
Dynamic Simulations ◽  
Constraint Equations ◽  
Revolute Joints ◽  
New Models ◽  
Analysis System ◽  
Aided Design ◽  
Algebraic Constraint

The development of new and complex vehicle models using the absolute nodal coordinate formulation (ANCF) and multibody systems (MBS) algorithms is discussed in this paper. It is shown how a continuum-based finite element (FE) leaf spring and tire assembly can be developed at a preprocessing stage and integrated with MBS algorithms, allowing for the elimination of dependent variables before the start of the dynamic simulations. Leaf springs, which are important elements in the suspension system of large vehicles, are discretized using ANCF FEs and are integrated with ANCF tire meshes to develop new models with significant details. To this end, the concept of the ANCF reference node (ANCF-RN) is used in order to systematically assemble the vehicle model using linear algebraic constraint equations that can be applied at a preprocessing stage. These algebraic constraint equations define new FE connectivity conditions that include the leaf spring shackle/chassis assembly, tire flexible tread/rigid rim assembly, tire/axle assembly, and revolute joints between different vehicle components. The approach presented in this paper allows for using both gradient deficient and fully parameterized ANCF FEs to develop the new models. In order to develop accurate leaf spring models, the prestress of the leaves and the contact forces between leaves are taken into consideration in the ANCF models developed in this investigation. Numerical results are presented in order to demonstrate the use of the computational framework described in this paper to build continuum-based leaf spring/tire assembly that can be integrated with complex vehicle models. The results of this paper also demonstrate the feasibility of developing a CAD (computer-aided design)/analysis system in which the geometry and analysis mesh of a complete vehicle can be developed in one step, thereby avoiding the incompatibility and costly process of using different codes in the flexible MBS analysis.

scholarly journals Computer-Aided Design of Cefuroxime Axetil/Cyclodextrin System with Enhanced Solubility and Antimicrobial Activity

Biomolecules ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 24 ◽  
Author(s):  
Mikołaj Mizera ◽  
Daria Szymanowska ◽  
Anna Stasiłowicz ◽  
Dominika Siąkowska ◽  
Kornelia Lewandowska ◽  
...  
Keyword(s):  
Theoretical Model ◽  
Computer Aided Design ◽  
Active Pharmaceutical Ingredient ◽  
Cefuroxime Axetil ◽  
Antimicrobial Efficacy ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Enhanced Solubility ◽  
Ft Ir ◽  
Aided Design

This study aimed to investigate changes in the solubility and antimicrobial efficacy of cefuroxime axetil (CA) when incorporated into cyclodextrin (CD). While choosing the CD, the validated in silico model was used. A theoretical model based on docking and molecular mechanics/generalized born surface area was validated using a curated dataset of API (active pharmaceutical ingredient)–CD stability constants. The library of commonly used cyclodextrins was virtually screened, indicating CA –hydroxypropyl-βCD (HPβCD) as the most thermodynamically favored system. Solid-state CA–HPβCD system was prepared and characterized by differential scanning calorimetry (DSC), Fourier-transform infrared (FT-IR), and X-ray diffraction (XRPD) methods. The dissolution profiles of the CA and its cyclodextrin system were evaluated. Microbiological activity of the CA–HPβCD inclusion system was studied based on changes in minimal inhibitory concentration (MIC) values and related to ones of the pure CA. The theoretical model was successfully validated, obtaining an average correlation with experimental data R = 0.7. The dissolution study showed significantly improved dissolution profiles of CA–HPβCD compared to CA. HPβCD increases the antimicrobial efficacy of CA up to 4-fold compared to pure CA.

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