ME9 Midterm 1

Surface Model

A CAD-generated model created to show a part as a collection of intersecting surfaces that bound a solid.

Morphological chart

A chart used to generate ideas about the desirable qualities of a product and all of the possible options for achieving them.

Circle

A closed curved figure where all points on it are equidistant from its center point.

Elipse

A closed curved figure where the sum of the distance between any point on the figure and its two foci is constant.

Family Model

A collection of different versions of a part in a single model that can display any of the versions.

Drawing

A collection of images and other detailed graphical specifications intended to represent physical objects or processes for the purpose of accurately re-creating those objects to processes.

Database

A collection of information for a computer and a method for interpretation of the information from which the original model can be re-created.

Assembly

A collection of parts that mate together to perform a specified function or functions

System

A collection of parts, assemblies, structures, and processes that work together to perform one or more prescribed functions.

Image

A collection of printed, displayed, or imagined patterns intended to represent real objects, data, or processes.

Mass Properties Analysis

A computer-generated document that gives the mechanical properties of a 3-D solid model.

Ground Constraint

A constraint usually applied to a new sketch to fix the location of the sketch in space.

Arc

A curved entity that represents a portion of a circle.

Holes

A cut feature added to a model that will often receive a fastener for system assembly.

Construction Line

A faint line used in sketching to align items and define shapes.

Protrusion

A feature created by the addition of solid volume to a model.

Master Feature

A feature or collection of features that is to be copied for placement at other locations in a model.

Mirrored Feature

A feature that is created as a mirror image of a master feature.

Child feature

A feature that is dependent upon the existence of a previously created feature.

Parent Feature

A feature used in the creation of another feature, which is called its child feature.

Model Tree

A list of all of the features of a solid model in the order in which they were created, providing a "history" of the sequence of feature creation.

Solid Model

A mathematical representation of a physical object that includes the surfaces and the interior material, usually including a computer-based simulation that produces a visual display of an object as if it existed in three dimensions.

Model

A mathematical representation of an object or a device from which information about its function, appearance, or physical properties can be extracted.

Weighted Decision Table

A matrix used to weigh design options to determine the best possible design characteristics.

Visual Thinking

A method for creative thinking, usually through sketching, where visual feedback assists in the development of creative ideas.

Feature Array

A method for making additional features by placing copies of a master feature on the model at a specified equal spacing.

Constructive Solid Geometry (CSG)

A method used to build solid models from primitive shapes based on Boolean set theory.

Boundary Representation (b-rep)

A method used to build solid models from their bounding surfaces.

Finite Element Analysis (FEA)

A numerical method used to analyze a product in terms of it structural

Sustainable Design

A paradigm for making design decisions based on environmental considerations and life cycle analysis.

Engineer (noun)

A person who engages in the art of engineering.

Profile

A planar sketch that is used to create a solid.

Sketching Plane

A plane where 2-D sketches and profiles can be created.

Vertex

A point that is used to define the endpoint of an entity such as a line segment or the intersection of two geometric entities.

Brainwriting

A process of group creative thinking where sketching is the primary mode of communication between team members.

Form Feature

A recognizable area on a solid model that has a specific function.

Oblique Axes

A set of three coordinate axes that are portrayed on the paper as two perpendicular lines, with the third axis meeting them at an angle, typically 45 degrees.

Isometric Axes

A set of three coordinate axes that are portrayed on the paper at 120 degrees relative to one another.

3-D coordinate System

A set of three mutually perpendicular axes used to define 3-D space

Tick mark

A short dash used in sketching to locate points on the paper.

Part

A single object fabricated to perform one or more functions.

Isometric Pictorial

A sketch of an object that shows its three dimensions where isometric axes were used as the basis for defining the edges of the object.

Oblique Pictorial

A sketch of an object that shows one face in the plane of the paper and the third dimension receding off at an angle relative to the face.

Sketching Editor

A software tool used to create and edit sketches.

Blend

A solid formed by a smooth transition between two or more profiles.

Double-sided extrusion

A solid formed by the extrusion of a profile in both directions from its sketching plane.

Revolved Solid

A solid formed when a profile curve is rotated about an axis.

Parametric Solid Modeling

A solid modeling system that allows the user to vary the dimensions and other parameters of the model.

Feature-based Solid Modeling

A solid modeling system that uses features to build models.

Swept Feature

A solid that is bound by the surfaces swept out in space as a profile is pulled along a path.

Extrusion

A solid that is bounded by the surfaces swept out in space by a planar profile as it is pulled along a path perpendicular to the plane of the profile.

Line

A spatial feature that marks the shortest distance between two points. A line has location, orientation, and length, but no area.

Bounding Box

A square box used to sketch circles or ellipses.

Horizontal Modeling

A strategy for creating solid models that reduces parent-child relationships within the feature tree.

Design Table

A table or spreadsheet that lists all of the versions of a family model, the dimensions or features that may change, and the values in any of its versions.

Descriptive geometry

A two-dimensional graphical construction technique used for geometric analysis of three-dimensional objects.

Driven Dimension

A variable connected to an algebraic constraint that can be modified only by user changes to the driving dimensions.

Driving Dimension

A variable used in an algebraic constraint to control the values of another (driven) dimension.

Extrude to the next surface

An extrusion begins at the profile and the protrusion or cut stops when it intersects the next surface encountered.

Blind Extrusion

An extrusion made to a specified length in a selected direction.

Extrude through all

An extrusion that begins on the sketching plane and protrudes or cuts through all portions of the solid model that it encounters.

Extrude to a selected surface

An extrusion where the protrusion or cut begins on the sketching plane and stops when it intersects a selected surface.

Cutting Plane

An imaginary plane that intersects with an object to form a cross section.

Corner Views

An isometric view of an object created from the perspective at a given corner of the object.

Design (noun)

An original manifestation of a device or method created for performing one own more useful functions.

Chamfers

Angled cut transitions between two intersecting surfaces.

Left-Handed System

Any 3-D coordinate system that is defined by the left-hand rule.

Right-handed System

Any 3-D coordinate system that is defined by the right-hand rule.

Wireframe Models

CAD models created using lines, arcs, and other 2-D entities to represent the edges of the part; surfaces or solid volumes are not defined.

Sketching

Collections of 2-D entities.

CAD

Computer-aided drawing. The use of computer hardware and software for the purpose of creating, modifying, an storing engineering drawings in an electronic format

Ribs

Constant thickness protrusions that extend from the surface of a part and are used to strengthen or stiffen the part.

Algebraic Constraints

Constraint that define the value of a selected variable as the result of an algebraic expression containing other variables from the solid model.

Geometric Constraints

Definitions used to control the shape of a profile sketch through geometric relationships.

CAD Designers

Designers who create 3-D computer models for analysis and detailing.

Features

Distinctive geometric shapes on solid parts; 3-D geometric entities that exist to serve some function.

Model Builders

Engineers who make physical mock- ups of designs using modern rapid prototyping and CAM equipment.

Cosmetic Features

Features that modify the appear- ance of the surface but do not alter the size or shape of the object.

Datum Geometries

Geometric entities such as points, axes, and planes that do not actually exist on real parts, but are used to help locate and define other features.

Constraints

Geometric relationships, dimensions, or equations that control the size, shape, and/or orientation of entities in a sketch or solid model.

Master Model

In a collection of similar parts, the model that includes all of the features that may appear in any of the other parts.

Boolean operations

In early versions of 3-D CAD software, commands used to combine solids.

Instruments

In engineering drawing, mechanical devices used to aid in creating accurate and precise images.

Project

In engineering, a collection of tasks that must be performed to create, operate, or retire a system or device.

Design Analysts

Individuals who analyze design concepts by computer methods to determine their structural, thermal, or vibration characteristics.

Shading

Marks added to surfaces and features of a sketch to highlight 3-D effects.

Two Dimensional (2-D) Drawing

Mathematical modeling or drawing where the appearance of parts, assemblies, or structures are represented by a collection of two-dimensional geometric shapes.

Three Dimensional (3-D) Modeling

Mathematical modeling where the appearance, volumetric, and inertial properties of parts, assemblies, or structures are created with the assistance of computers and display devices.

Dimensional Constraints

Measurements used to control the size or position of entities in a sketch.

Variational Techniques

Modeling techniques in which algebraic expressions or equations that express relationships between a number of variables and constants, any one of which can be calculated when all of the others are known.

Parametric Techniques

Modeling techniques where all driven dimensions in algebraic expressions must be known for the value of the dependent variables to be calculated.

Optimization

Modification of shapes, sizes, and other variables to achieve the best performance based on predefined criteria.

Isometric Dot Paper

Paper used for sketching purposes that includes dots located along lines that meet at 120 degrees.

Isometric Grid Paper

Paper used for sketching purposes that includes grid lines at 120 degrees relative to one another.

Splines

Polynomial curves that pass through multiple data points.

Architects

Professionals who complete conceptual designs for civil engineering projects.

Unsuppressed

Refers to the option for displaying a selected feature.

Suppressed

Refers to the option for not displaying a selected feature.

Shelling

Removing most of the interior volume of a solid model, leaving a relatively thin wall of material that closely conforms to the outer surfaces of the original model.

Associative Constraints

See algebraic constraints.

Feature Pattern

See feature array.

Design Tree

See model tree.

Feature Tree

See model tree.

History Tree

See model tree.

Trajectory

See path.

Webs

Small, thin protrusions that connect two or more thicker regions on a part.

Rounds

Smooth radius transitions of external edges created by two intersecting surfaces and tangent to both intersecting surfaces.

Fillets

Smooth transitions of the internal edge created by two intersecting surfaces and tangent to both intersecting surfaces.

Spatial Orientation

The ability of a person to mentally determine his own location and orientation within a given environment.

Visualization

The ability to create and manipulate mental images of devices or processes.

Spatial Perception

The ability to identify horizontal and vertical directions.

Spatial Visualizations

The ability to mentally transform (rotate, translate, or mirror) or to mentally alter (twist, fold, or invert) 2-D figures and/or 3-D objects.

Mental Rotations

The ability to mentally turn an object in space.

Spatial Relations

The ability to visualize the relationship between two objects in space, i.e., overlapping or nonoverlapping.

Life Cycle

The amount of time a product will be used before it is no longer effective.

Parameters

The attributes of features, such as dimensions, that can be modified.

Symmetry

The characteristic of an object in which one half of the object is a mirror image of the other half.

Concept Mapping

The creative process by which the central idea is placed in the middle of a page and related concepts radiate out from that central idea.

Base Feature

The first feature created for a part, usually a protrusion.

Problem Identification

The first stage in the design process where the need for a product or a product modification is clearly defined.

Graphical User Interface (GUI)

The format of information on the visual display of a computer, giving its user control of the input, output, and editing of the information.

Chief Designer

The individual who oversees other members of the design team and manages the overall project.

Detail Designers

The individuals who create engineering drawings, complete with annotation, from 3-D computer models or from engineering sketches.

Industrial Designers

The individuals who use their creative abilities to develop conceptual designs of potential products.

Prototype

The initial creation of a product for testing and analysis before it is mass-produced.

Conceptual Design

The initial idea for a design before analysis has been performed.

Cross Section

The intersection between a cutting plane and a 3-D object.

As-built Drawings

The marked-up drawings from a civil engineering project that show any modifications implemented in the field during construction.

Design Process

The multistep, iterative process by which products are conceived and produced.

Principal Viewing Planes

The planes in space on which the top, bottom, front, back, and right and left side views are projected.

Primary Modeling Planes

The planes representing the xy-, xz-, and yz-planes in a Cartesian coordinate system.

Datum Planes

The planes used to define the locations of features and entities in the construction of a solid model.

Receding Dimension

The portion of the object that appears to go back from the plane of the paper in an oblique pictorial.

Computer-aided Design (CAD)

The process by which computers are used to model and analyze designed products.

Concurrent Engineering

The process by which designers, analysts, and manufacturers work together from the start to design a product.

Green Engineering

The process by which environmental and life cycle considerations are examined from the outset in design.

Engineering Design

The process by which many competing factors of a product are weighed to select the best alternative in terms of cost, sustainability, and function.

Computer-Aided Manufacturing (CAM)

The process by which parts are manufactured directly from 3-D computer models.

Design (verb)

The process of creating a design (noun).

Combining Solids

The process of cutting, joining, or intersecting two objects to form a third object.

Brainstorming

The process of group creative thinking used to generate as many ideas as possible for consideration.

Reflection

The process of obtaining a mirror image of an object from a plane of reflection.

Regeneration

The process of updating the profile or part to show its new shape after constraints are added or changed.

Engineering

The profession in which knowledge of mathematical and natural sciences gained by study, experience, and practice is applied with judgment to develop and utilize economically the materials and forces of nature for the benefit of humanity.

Design Documentation

The set of drawings and specifications that illustrate and thoroughly describe a designed product.

Primitives

The set of regular shapes, such as boxes, spheres, or cylinders that are used to build solid models with constructive solid geometry methods (CSG).

Path

The specified curve on which a profile is placed to create a swept solid.

Dimension Name

The unique alphanumeric designation of a variable dimension.

Volume of interference

The volume that is common between two overlapping objects.

Solid Modeling

Three-dimensional modeling of parts and assemblies originally developed for mechanical engineering use but presently used in all engineering disciplines.

Join

To absorb the volume of interference between two objects to form a third object.

Intersect

To create a new object that consists of the volume of interference between two objects.

Fabricate

To make something from existing material.

Engineer (verb)

To plan and build a device that does not occur naturally within the environment.

Cut

To remove the volume of interference between two objects from one of the objects.

Right-hand Rule

Used to define a 3-D coordinate system whereby by pointing the fingers of the right hand down the x-axis and curling them in the direction of the y-axis, the thumb will point down the z-axis.