Course Title: Analyse force systems (advanced)

Part B: Course Detail

Teaching Period: Term1 2010

Course Code: CIVE5675

Course Title: Analyse force systems (advanced)

School: 130T Vocational Engineering

Campus: City Campus

Program: C6093 - Advanced Diploma of Engineering Design

Course Contact: Program Manager

Course Contact Phone: +61 3 9925 4468

Course Contact Email: vocengineering@rmit.edu.au


Name and Contact Details of All Other Relevant Staff

Nominal Hours: 60

Regardless of the mode of delivery, represent a guide to the relative teaching time and student effort required to successfully achieve a particular competency/module. This may include not only scheduled classes or workplace visits but also the amount of effort required to undertake, evaluate and complete all assessment requirements, including any non-classroom activities.

Pre-requisites and Co-requisites

EDX130B – Use technical mathematics (basic)
EDX140B – Use technical mathematics (advanced)
EDX100B – Analyse force systems (basic)

Course Description

This unit covers the competency to extend basic skills and knowledge in calculating forces, moments and stresses to AQF level 5. It brings the level of competency in force and stress analysis to that needed to commence design calculations in either the mechanical or structural field using Australian and/or ISO Design Standards.


National Codes, Titles, Elements and Performance Criteria

National Element Code & Title:

EDX190B Analyse force systems (advanced)

Element:

Solve problems using the laws of dry sliding friction.
Determine support reactions for determinate structures.
Determine the internal forces acting on members of a pin jointed truss.
Determine the pin reactions of a pin jointed frame.
Determine pin and support reactions for a simple noncoplanar non-concurrent force system
Determine bolt sizes or number of bolts required for simple bolted connections.
Determine the nominal weld size or length of weld required on simple welded connections
Determine wall thickness in thin walled cylinders subjected to pressure
Calculate shaft size and angle of twist for simple circular shafts subject to torques
Use Johnson or Euler equations to determine buckling loads
Determine the thermal stress in single members caused by restraint and changes in temperature

Performance Criteria:

1.1 The principle of limiting friction and the friction angle can be explained.
1.2 Problems are solved using the laws of dry sliding friction for objects on horizontal and inclined planes.
1.3 Problems are solved using the laws of dry sliding friction that involve the use of moment equations.

2.1 The support with a reaction in a known direction can be recognised and the direction described.
2.2 A Free Body Diagram can be drawn of a loaded structure showing the support reactions.
2.3 Support reactions (magnitude & direction) can be determined, using the principles of equilibrium.

3.1 The Method of Joints can be used to determine the internal forces acting on all members of a simple pin jointed truss.
3.2 A combined force polygon (Maxwell Diagram) can be used to determine the internal forces acting on all members of a simple pin-jointed truss.
3.3 The Method of Sections can be used to determine the internal forces acting on members of a simple pin-jointed truss.

4.1 The Method of Members can be used to determine the forces acting on the pins of a simple pin jointed frame or machine.

5.1 Given a simple shaft or trapdoor system, the magnitude of the components of the forces at supports, pins or hinges can be determined.

6.1 The correct use of a standard bolt data table is demonstrated.
6.2 Calculations are completed to determine the size or number of bolts required for simple bolted connections.
7.1 Calculations are completed to determine the size and length of welds for simple welded connections subjected to direct shear only.

8.1 The equations for Hoop stress and longitudinal stress are used to calculate stresses in thin walled vessels subject to pressure.
8.2 The equations for hoop stress and longitudinal stress are used to determine the required minimum wall thickness for thin walled vessels.
8.3 A Factor of Safety is applied in calculations involving thin walled vessels subjected to pressure.

9.1 The torsional shear stress formula is used to calculate torsional shear stress and angle of twist in a circular shaft for a given torque load.
9.2 Torque distribution diagrams are sketched to determine maximum torque for shafts involving several power takeoff points.
9.3 The torsional shear formula is used to calculate the nominal diameter of a simple circular shaft for a given torque load.
9.4 A shaft size is calculated for a simple shaft to meet a requirement for maximum stress or maximum angle of twist.

10.1 The column is analysed to determine whether the Johnson or Euler equation can be used.
10.2 End fixing conditions are analysed to determine the effective length.
10.3 The buckling load is calculated.

11.1 Calculations are carried out to determine thermal stress in simple members caused by full or partial restraint and changes in temperature.


Learning Outcomes


Refer to the Elements


Details of Learning Activities

Demonstrate the design process for simple bolted and welded connections using manufacturer’s load capacity tables and appropriate Standards.
Overview the analysis of frames to determine both internal member forces and pin reactions.
Review prior studies in EDX100 covering reactions for determinate structures.
Describe the significance of friction effects in Civil applications, e.g. stability of slopes and retaining walls, and work through sample calculations.
Present formulae and explain the meaning of symbols for thin walled cylinders, shafts, buckling loads and thermal stresses.
Carry out sample calculations on the above.

Problem-solving :
Participate in individual problem solving activities completed to industry standard related to typical engineering workplace problems requiring determination of:
* Support reactions for determinate structures
* Internal member forces and pin reactions in a truss
* Pin and support reactions for non-coplanar, non-concurrent force system
* Bolt and weld sizes for a connection
* Cylinder wall thickness, shaft sizes, column buckling loads and thermal stresses
* Through discussion determine the effective length of columns in resisting buckling, given examples of end restraints for industrial buildings.
* Collaborate to determine examples of the use of pressure vessels and circular shafts in civil engineering applications.
* Discuss how friction can be of assistance in structural design


Teaching Schedule

See Online Learning Hub for details.


Learning Resources

Prescribed Texts

Engineering Mechanics, Val Ivanhoff


References

Structural Mechanics (Ed. 6), Durka


Other Resources


Overview of Assessment

Assessment are conducted in both theoretical and practical aspects of the course according to the performance criteria set out in the National Training Package. Students are required to undertake summative assessments that bring together knowledge and skills. To successfully complete this course you will be required to demonstrate competency in each assessment tasks detailed under the Assessment Task Section.

Your assessment for this course will be marked using the following table:

NYC (<50%) Not Yet Competent

CAG (50-59%) Competent - Pass

CC (60-69%) Competent - Credit

CDI (70-79%) Competent - Distinction

CHD (80-100%) Competent - High Distinction


Assessment Tasks

Assessment of this unit will involve completion of:
• a two hour mid-semester written examination on Elements 1 – 5
• a two hour end-of-semester written examination on Elements 6 – 11
The format of the examination will include case studies and scenarios based on typical workplace activities to support problem-based assessment of ability to accurately complete calculations to industry standards


Assessment Matrix

Other Information

Underpinning knowledge and skills
Prerequisite units comprise part of the underpinning knowledge and skills.
Friction:- Coefficient of frictional resistance
Laws of dry sliding friction
The angle of friction
The angle of repose
Friction on inclined planes
Resultant of normal reaction and friction force
Stability – overturning versus sliding
Application to other non-concurrent force systems
Support Reactions:- Types of support
Analysis of support conditions to recognise reactions in known directions
Development of free-body-diagram for solving of support reactions
Application of equations of equilibrium to solving support reactions
Trusses and frames:- Two-force and three-force members
Definition of truss and frame
Solving forces in members of a truss
Method of Joints
Method of Sections
Maxwell Diagrams (combined force polygon)
Solving forces at pins in a frame or machine
Method of Members
Three-dimensional force systems:-
Forces on shafts
Forces on simple three dimensional frames
Free-body-diagrams required
Solving for forces in three dimensional space
Centrally loaded connections:-
Bolted connections
Shear, tensile and bearing stresses
Threads in the shear plane
Extraction of appropriate area from bolt data tables
Centrally loaded welded connections
Fillet and butt welds
Method of failure
Size and length of weld required
Thin walled pressure vessels:-
Definition of thin walled
Concepts of longitudinal and hoop stress
Determination of longitudinal stress
Determination of hoop stress
Buckling loads:- Principles of buckling
Analysis of fixing conditions
Determination of effective length
Determination of slenderness ratio
Choice of Euler or Johnson formula
Application of Johnson or Euler formula to determine buckling load.
Thermal expansion and stress:-
Coefficient of linear expansion
Thermal stresses in single members
Full and partial restraint
Torsional shear stress:- Torque diagrams
Angle of twist
Torsional shear stress formula
Design of simple shafts using shear stress formula

Course Overview: Access Course Overview