computer aided design Flashcards
what could CAD modelling include
- creating and modifying designs in 3D
- Graphic/interior design
- Data processing
- Finite element analysis
- Simulations
- Creating and modifying designs
what other type of modifications can take place
> design features - changing form of parts, adding features to an design, rearranging
> material modifications
> changing size of parts
> changing aesthetics through rendering different materials
Graphic/interior design
- creating of logos
- Creation of murals/ artistic drawings
- Architectural design
- Design layout of fixtures/ furnishings within a given room/ space
Data processing
- technical data/dimensions of a product usually shown in 2D (through DWG for fusion 360)
- Parametric modelling
Finite element analysis
- the calculations and simulation of unknown factors in products using CAD systems. For example, simulating the stresses within a prosthetic limb
Motion simulations
simulation parts of a design or mechanisms to move to check functionality or desired outcome
Advantages of CAD modelling
- changes to ideas can be made quickly and easily without deleting ideas
- Easy to repeat features, create patterns, quick rendering of material/colour
- Ideas look more realistic
- Communicate with client, manufacture more easily electronically
- Avoid costly mistakes as CAD models can provide aesthetic overview, form and shape study, motion simulation, FEA analysis for studying loads
- High level of accuracy/fidelity in dimensioning and intricacy of features
Disadvantages of CAD modelling
- software may be expensive
- There may be a steep learning curve
- Quick and fast conceptual sketches where dimensioning is not critical may take more time with CAD
Surface vs solid modelling
- surface modelling: models the surface of the product without showing internal details
- Solid modelling: clear representation of the final products, all internal parts are included
Bottom up vs top down modelling
top down:
> design originates as a whole concept, and gradually evolves into a whole product consisting of components and sub assemblies
> design of parts have to fit into overall product criteria and there maybe greater communication among designers of sub-components
bottom up
> focus is on individual part modelling, design criteria are more focused for the individual part
> criteria may not be shared between models
> after individual parts are designed, they are then assembled together to make the whole product
Data modelling (including statistical modelling)
- it is modelling that determines the structure of data
- Can be diagram accompanied by data
- Can be statistical chart
- Can be a pure database model consisting of just numbers and categories/labels
- Database models can be flat file, relational or hierarchical
Database model types
flat file, relational database, hierarchical database
flat file
> single table of data
> no interrelationship between data sets
relational database
> two or more tables of data that are linked
> it can pull data from different tables and reassembles it
hierarchical database
a clear hierarchy exists between different sets of data, can be arranged in tree like structure
Virtual prototyping
- software driven modelling process that stimulates products and environments by mimicking real world behaviours
- Widely used in developing and testing of products
- Designers and engineers can simulate visually and also mathematically the design, assembly, and in-service use of complex products in range of environments and scenarios
- Process is faster, cost is reduced, more environment friendly due to minimisation of materials, design process shortened
Nasa used virtual prototyping to stimulate assemble process of the stardust spacecraft
Digital humans
- computer simulations of the biomechanics of the human body
- Help to predict how a human (real) will react in a variety of situations or environments (places or locations)
- Can be used to represent joint resistance, discomfort, reach envelops and visual field and study ergonomics
- Can be used in training and performance
- Can be used in e-commerce, for example to model clothing products
DH - motion capture
- employed to assist with the understanding of human factors, physical limitations of users, product evaluation as well as training and performance
- Used to record, track and analyse movement
- Special markers applied to strategic points of a moving body to identify key pieces of geometry
- Resultant changes in position are recorded and digitised for playback and analysis
- Focus on movement not visual appearance of the human
- Can also be able to derive physiological indices such as heart rate, breathing rate
Advantages of digital humans using motion capture in product design
- test and evaluate product based on ergonomic factors
- Takes into account range of sizes and shapers of users
- Consider user safety factors in a range of environments
- Review human factors in design before building prototypes
- Save time and expensive resources
Haptic technology
- emerging technology that interfaces the user via sense of touch
- Generally mechanical actuators apply forces to the user which gives them feedback. Simplest example would be a phone vibration
- Allows user to become part of a computer simulation and to interact with it, enabling the designer to observe the user’s performance and to design a better outcome
- Can be used for training or simulation of scenarios which are remote or dangerous or touch virtual objects which could be delicate
- Commonly used in gaming like wifi where user feels a touch sensation when in the game
Virtual reality and animation
- the ability to simulate a real situation on the screen and interact with it in a near natural way
- animations help engineers understand complex mechanisms and alter design and components as required to alter outcome
- Helps to advance real time training
- Reduce product development cycles
- Save resources by removing reliance on physical modelling
