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WHAT IS A WELDMENT?
http://winman.ca/portfolio/weldments.htm
WHERE ARE WE IN THE DESIGN PROCESS?
ENGINEERING
SIMULATION AND
ANIMATION
Engineering
Simulation
CAD
QFDFUNCTIONAL DECOMPOSITION
DECISION MATRIX
DESIGN
PROTOTYPING
TESTING
PRODUCTION
CAD
PROTOTYPING
TESTING
PRODUCTION
SIMULATION
FEA
Windows OS
solid CAD
TRADITIONAL PRODUCT
DESIGN PROCESS
SIMULATION DRIVEN PRODUCT
DESIGN PROCESS
affordable computers
EVOLUTION OF DESIGN PROCESS
ENGINEERING DESIGN MODELS
STRUCTURE Descriptive and graphical
e.g. diagrams of how elements are connected and arranged
FUNCTION Generally abstract
e.g. mathematical models
FORM Descriptive and graphicale.g. drawings of parts and assemblies
FORM, FUNCTION AND STRUCTURECAE models
CB
EQ1
R1
R3
3
C2
+R6
R8
R4
R7
R5
LENS
LED
+9VMIC C1
+
+ - 741
R2
2
4 76
Power Supply
Components:
741 OP AMP R1 = 50 k (Variable) R2 = 1 M R3 = 5.6 k R4 = 5.6 kR5 = 1 k R6 = 50 k (Variable) R7 = 1 kR8 = 220
C1 = 0.1 mF C2 = 10 mF Q1 = 2N3904LEDMIC : MicrophoneVcc = 9 V
Power SupplyOutput
Ground
MICROPHONE with two wires:
MIC
2.2 k
1 F
1
2
AM Light Wave Transmitter
STRUCTURE
INPUT
Reference value AmplifierRotating Shaft
OUTPUT
Constant speed shaftMotor
Measurement Tachnogenerator
Differential amplifier
Shaft Speed Control
System diagram of a shaft speed control
FUNCTION
FUNCTION
Vibration of a single degree of freedom system
2 2 2 coso d k e mI cl kl m e l t
3
3 y
Plf
EI
Deflection of a cantilever beam
Ackerman steering geometry is defined by angling the steering arms so that a line drawn between both the king pin and steering arm pivot points intersects with the centre line of the rear axle.
FUNCTION
System diagram of a car steering
Transfer Function - is the input-output relationship of a system (or subsystem).
OUTPUT = TRANSFER FUNCTION X INPUT Example:For a gear box: output angular velocity = C X input angular velocity where C is some constant (i.e. transfer function).
FUNCTION
Model captures FUNCTION but not FORM
transfer function.SLDASM
FORM – Engineering Drawings
Layout Drawing – drawn to scale but does not show tolerances, and is subject to change as the design process continues.
Detail Drawing – includes tolerances and indicates materials & lists special processing requirements. Drawn in conformance with ANSI drawing standards.
FORM – Engineering Drawings
FORM – Engineering Drawings
Detail Drawing – includes tolerances and indicates materials & lists special processing requirements. Drawn in conformance with ANSI drawing standards.
Assembly Drawing – uses an exploded view to show how some of the individual parts fit together. Components are identified by a part number or entry on an attached bill of materials.
FORM – Engineering Drawings
Typical assembly drawing with parts list.
FORM – Engineering DrawingsInformation on a Bill of Materials:
1. The item number or letter. This is a key to the components on the assembly drawing.
2. The part number.This number is used throughout the purchasing, manufacturing, inventory control, and assembly system to identify the component.
3. The quantity needed in the assembly.
4. The name or description of the component.This must be a brief, descriptive title for the component.
5. The material from which the component is made.If the item is a subassembly, then this does not appear in the BOM.
6. The source of the component.If the component is purchased, then the name of the company is listed.
BILL OF
MATERIALS
(BOM)
COMPUTER AIDED ENGINEERING (CAE) TOOLS IN MME2259a
CAD• geometric modeling of parts and assemblies• drafting• visualization (eg. shading, photo-rendering)
SIMULATION TOOLS• Motion animation (SOLIDWorks)• Structural analysis (Simulation Express)
The use of Simulation Express is not
required in the Design Project.
Familiarity with Simulation Express is
required to pass CSWA (10% bonus)
exam.
Use of Motion Analysis is
required in the Design
Project
Deciding Which Type of Study to Use
Use Animation to create presentation-worthy animations for motion that does not require accounting for mass or gravity.
Use Physical Simulation to create presentation-worthy approximate simulations of motion that account for mass, collisions, or gravity.
Use Motion Analysis to run computationally strong simulations that take the physics of the assembly motion into account. This tool is the most computationally intensive of the three options. The better your understanding of the physics of the motion you require, the better your results. You can use Motion Analysis to run impact analysis studies to understand component response to different types of forces.
MOTION ANALYSIS
DIFFERENCE BETWEEN A MECHANISM AND A STRUCTURE
Structure is firmly supported, mechanism is not.
Mechanism moves without having to deform its components. Mechanism components move as rigid bodies. Generally, a mechanism is designed to move. Mechanism has Rigid Body Motions (RBM).
Structure does not have Rigid Body Motions, any movement of a structure must involve deformation.
It may be one time deformation when the static load is applied or vibration about its neutral position (point of equilibrium). Generally a structure is designed to stand still.
COMMON KINEMATIC PAIRS
(MECHANISM COMPONENTS)
Revolute
1 DOF left
cylindrical
2 DOF left
Spherical
3 DOF left
Translational (prismatic)
1 DOF left
Planar
3 DOF left
Percentile
One of a set of points on a scale arrived at by dividing a group into parts in
order of magnitude.
For example, a score equal to or greater than 97 percent of those attained
on an examination is said to be in the 97th percentile.
Estimates proportions of the data that should fall above and below a given
value.
WHAT IS A PERCENTILE?
SIZE VARIATIONS IN A POPULATION
In general body heights and body lengths do vary uniformly in
a population because they depend upon bone structure.
Taller than 97.5% of population
Taller than 50% of population
Taller than 2.5% of population
WEIGHT VARIATIONS IN A POPULATION
In general weights and widths may not vary uniformly since these measurements depend upon age, amount of body fat, musculature, etc.
Range-of-Motion
R.J. Eggert, Engineering Design, Prentice-Hall:Upper Saddle River NJ, 2005, pp. 262.
ANTHROPOMETRIC DATA
R.J. Eggert, Engineering Design, Prentice-Hall:Upper Saddle River NJ, 2005, pp. 263.
Range-of-Motion
ANTHROPOMETRIC DATA
R.J. Eggert, Engineering Design, Prentice-Hall:Upper Saddle River NJ, 2005, pp. 264.
Range-of-Motion
ANTHROPOMETRIC DATA
Muscle Strength for 95th Percentile Males
R.J. Eggert, Engineering Design, Prentice-Hall:Upper Saddle River NJ, 2005, pp. 258.
ANTHROPOMETRIC DATA
Static Muscle Strength for Vertical Pull
R.J. Eggert, Engineering Design, Prentice-Hall:Upper Saddle River NJ, 2005, pp. 2598.
ANTHROPOMETRIC DATA