A method is presented for explicitly representing dimensions, tolerances, and geometric features in solid models. The combines CSG boundary representations a graph structure called an object graph. Dimensions are represented by relative position operator. can automatically translate changes dimensional values into corresponding geometry topology. representation provides important foundation higher-level application programs to automate tolerance analysis synthesis. implementation of...

A system has been developed which utilizes variational geometry in the design and modification of mechanical parts. Three-dimensional constraints between characteristic points are used to define an object's geometry. Modification is accomplished by alteration one or more constraints. matrix method determine shape part simultaneous solution constraint equations. for increasing speed efficiency procedure described. The uses relationships minimize number equations variables be solved.

A manufacturing system consists of the following processes; design, materials selection and processing, assembly, quality control. Maximum productivity a given can be obtained only through optimization entire rather than its components individually. optimized either thorough understanding interactions between components, i.e., an algorithmic approach; or application axioms to each decision-making step. This paper discusses axiomatic approach methodology for developing axioms. Several...

A system has been developed which utilizes variational geometry in the design and modification of mechanical parts. Three-dimensional constraints between characteristic points are used to define an object's geometry. Modification is accomplished by alteration one or more constraints. matrix method determine shape part simultaneous solution constraint equations. for increasing speed efficiency procedure described. The uses relationships minimize number equations variables be solved.

A procedure for defining and recognizing shape features 3-D solid models is presented in which a feature defined as single face or set of continuous faces possessing certain characteristic facts topology geometry. The system automatically extracts these from an example interactively indicated by the user. resulting representation can be edited parameterized. Graph matching accomplishes recognition. searches model B-rep subgraphs with same to recognized. When recognizes feature, it removes...

Advances in computer hardware and software engineering methodologies the 1960s 1970s led to an increased use of computers by engineers. In design, this has been limited almost exclusively algorithmic solutions such as finite-element methods circuit simulators. However, a number problems encountered design are not amenable purely solutions. These often ill structured (the term ill-structured is used here denote that do have clearly defined solution), experienced engineer deals with them using...

In this paper, a method is proposed for the design optimization of structural components where both shape and topology are optimized. The boundaries structure represented using contours “shape density” function. contour density function corresponding to threshold value defined as boundary shape. over feasible domain by continuous piece-wise interpolation finite elements used analysis. values at nodes serve variables problem. advantage representation that can be modified optimized algorithm....

An adaptive controller for a pressbrake has been designed, built, and tested. The measures force displacement during the early part of bend cycle to estimate workpiece parameters. These parameters are used in an elastic-plastic material model predict correct final punch position yield desired unloaded angle. A microcomputer is control Cincinnati CB90 hydraulic pressbrake. Data acquisition computation times short enough minimum flank angle 15 deg using standard forming rate 6.7 mm/s (16...

This paper investigated the use of graphite with different configuration designs to improve thermal energy storage phase change material systems. Two types have been combined paraffin in order conductivity material: synthetic (Timrex SFG75) and waste obtained from damaged tubular heat exchangers. Paraffin/graphite composites prepared by cold uniaxial compression technique. Their morphologies observed analyzed scanning electron microscope, their thermophysical properties estimated using new...

Dimensional variations often cause expensive problems in the assembly of mechanical products especially during new product deployment. Currently, time and labour spent on removal variation-related are considerable. This paper proposes a computational method to identify causes assemblies. In proposed method, relationship between symptoms is computed via simulation process, they represented by matrix. For given measurement data, this uses linear optimization statistical techniques diagnose...

The process of locating components in an available space while satisfying spatial relationships among the is called packaging. task requires extensive reasoning about geometric shapes. It a generic design common to many domains. also very time-consuming, especially as machines become more compact and complex. This paper describes progress toward automation packaging problem. An approach proposed determine optimal locations assembly from between components. utilizes novel combination...

This article deals with laminar natural convection in three-dimensional air-filled enclosures. The cavities under investigation have two opposite isothermal vertical walls and four adiabatic walls. horizontal aspect ratios are the range 5–80 0.2–5, respectively. Rayleigh numbers vary between 10 3 5 . These values match typically found hollow alveolar bricks. effects of geometry number on discussed. Comparisons purely two-dimensional cases results obtained 3D presented analyzed. Nusselt...

Abstract The process of locating components in an available space while satisfying spatial relationships among the is called packaging. task requires extensive reasoning about geometric shapes. It a generic design common to many domains. also very time-consuming, especially as machines become more compact and complex. This paper describes progress toward automation packaging problem. An approach proposed determine optimal locations assembly from between components. utilizes novel combination...