DT topic 3

2.1 Conceptual modeling

Originates in the mind, and its primary purpose is to outline the principles, processes and basic functions of a design or system

2.2 Freehand drawing

The spontaneous representation of ideas on paper without the use of technical aids

AD of freehand drawing

They are quick to produce & would be used for design dev.

Isometric drawings

A 3d rep. of an object with all vertical lines drawn vertically, and all horizontal lines drawn at 30° to the base line

Exploded iso-drawing

An iso-drawing of an object with multiple components that illustrates how the parts of assemblies fit together

Perspective drawing

A 3d drawing that realistically represents objects by utilizing foreshortening & vanishing points (usually imaginary ones)

Orthographic drawing

A series of 2D views of an object showing it exactly as it is in shape & size

Working drawings (also known as production or manuf. drawings)

Drawings that supply information & guidance for the manufacture of products

The choice of graphical models

The choice varies in relation to contexts, as each graphical model is used to develop different aspects of the design as well as to communicate to a range of different audiences

3.3 Physical modelling

a 3D, tangible repr of a design or system

Scale models

A smaller or larger physical copy of an object

Mockups

Scale or full-size repr. of a product used mainly to get users feedback

Aesthetic models (or app. prototype)

Full-sized repr. of a product that looks & feels like the final product but does not work like it

Prototypes

Working models of a product or system are created to test a concept/process, gather u.f, to infor dec. or to be replicated

The range of contexts

1. Restricted: in a controlled env

2. General: any user, any env

3. Partial: final user or final env

4. Total: final user and final env

Instrumented

Equipped with the ability to take measurements (instrumented), to provide accurate quantitative feedback for analysis

3.4 CAD

The generation, creation, dev & analysis of a design using computer software

AD of CAD

Enhanced presentation of ideas, enhanced comm, virtual protot, & virtual testing

DA of CAD

Expensive, requires training

Finite element analysis (FEA)

The calculation & stimulation of unknown factors in products using CAD

Animation

The ability to link graphic screens together in a way that stimulates motion or a process

VR

The ability to stimulate motion on a screen & to interact with it in a near natural way

Haptic tech.

Force feedback tech. that influences the user via the sense of touch

DIgital humans

Computer stim. of a variety of the mechanical & biological aspects of the human body

Motion capture tech.

The recording of human and animal movements by any means

VP

The use of surface and solid modeling to test the interactive models

Rapid prototyping

The production of a physical model for a design using 3D CAD data

Additive joining teq.

Deposits molten material in a series of layers

Subtractive joining teq.

Removes (cut) unwanted material from a block

Stereolithography (SLA)

An additive man. tech. that builds 3D models using a photosensitive liquid resin that hardens when lazer hits it

Selective lazer sintering (SLS)

uses small particles of plastic (sand) that hardens when lazer hits it

Fused deposition modeling (FDM)

extrudes melted thermoplastic filament through a nozzle to build 3D objects layer by layer.

Laminated object man. (LOM)

uses layers roll material, laminates that are bonded together, then cut to shape with a laser