There are many problems in which the available information is not precise enough to justify the use of numbers. In many engineering problems we cannot precisely measure the exact values of loads (e.g. wind loads, weight of vehicle etc.), material constant (particularly in bimechanics, geomechanics, wall structures, concrete structures and composite structures) and geometric characteristic (tole...

A practical example of B-spline curve control points manipulation for the geometric construction of a free form shape is presented. Elements of a cross-sectional design methodology are used in conjunction with a skinning type operator for the definition of a B-spline surface. Skinning process are well established in the CAD community but further difficulties arise in producing smooth surfaces u...

* Capture and publish Product Manufacturing Information (PMI) and 3D documentation such as Geometric Dimensions and Tolerances (GD&T), manufacturing symbols, and notes * Create highly compressed 3D PDF documents to enable 3D-based collaboration * Share 3D PDF documents and view with Adobe Reader * Visualize 3D PDF documents with pan, zoom, and rotate including options to turn parts and assembli...

In order to investigate the performance of suprathreshold color-difference tolerances with different visual scales and different perceptual correlates, a psychophysical experiment was carried out by the method of constant stimuli using CRT colors. Five hue circles at three lightness (L*=30, 50, and 70) and chroma (C*ab=10, 20, and 30) levels were selected to ensure that the color-difference tol...

Process tolerancing based on the process capability studies is the optimistic and pragmatic approach of determining the manufacturing process tolerances. On adopting the define–measure–analyze–improve–control approach, the process potential capability index (C p) and the process performance capability index (C pk) values of identified process characteristics of connecting rod ...

Solid Freeform Fabrication, SFF, is a set of manufacturing processes that fabricates parts as a bonded stack of individual layers. The Three Dimensional Printing process, 3DPTM process, is an SFF technology developed at MIT. It builds layers by ink jet printing binder onto the surface of a bed of powder. The bed of powder is lowered and fresh powder is spread onto the bed. As subsequent cross s...

The purpose of this research is to investigate a computer-aided approach to tolerance analysis for assemblies and mechanisms. A CAD system which can generate NURBS surfaces is used to produce imperfect-form, variant models. A method is developed for simulating the mating of these imperfect-form components by formulating surface mating relationships as a nonlinear programming problem. Using this...