Using CES software (using Level 2 Database, Edu Level 2 Materials subset), prepare the following materials selection charts (y-axis variable listed first): 1.1 Yield Strength -v- Density: (σy -v- ρ)

MODULE CODE:	EAT104
MODULE TITLE:	Materials & Manufacturing

Materials Properties and Materials Selection

 

Introduction

 

Engineers design and make things.  Let’s assume we’re talking about engineering components.  These components are made of MATERIALS (metal, plastic, ceramic, composite etc.).  The best material from which to make any given component depends on a number of factors (e.g. mechanical, thermal or electrical properties, density, cost, environmental impact etc.) and the process by which the final material is chosen is MATERIALS SELECTION.  In this module we use a well-established graphical methodology for materials selection based on quantitative measures of performance called PERFORMANCE INDICES.  This methodology is the one employed within the CES 2017 software - and part of the aim of this assignment is that you become familiar with the use of this software.  You will be using it in all 3 years of your degree.

TASK 1

 

Using CES software (using Level 2 Database, Edu Level 2 Materials subset), prepare the following materials selection charts (y-axis variable listed first):

 

1.1 Yield Strength -v- Density: (σ_y -v- ρ)

1.2 Yield Strength -v- (Price x Density): (σ_y -v- C_m ρ)

1.3 (Young’s Modulus)^1/2 / Density  -v-  (Yield Strength)^2/3 / Density: 

      [(E^1/2/ρ)  -v-  (σ_y^2/3/ρ)]

Copy/Paste your charts from CES into your report.  Label and format the charts in your chosen style. Give a brief commentary on your work.

In class you have learned to take a given performance index (M) and use this:

(i) to plot the appropriate selection chart, and

(ii) apply a selection line of given gradient to allow the selection process to proceed

[In essence, if a performance index, M, is given by:  

……where Y and X are the relevant material properties. The correct selection chart is log Y  -v-  log X and the correct selection line will possess a gradient of n.]. Note that CES defaults to log plots when creating charts.

 

TASK 2

Using the 2 charts you have already prepared in Task 1.1 and 1.2, insert an appropriate selection line and thereby determine a shortlist of the best 10-15 materials for each of the following (2.1 and 2.2). 

2.1 A strong circular cross-section beam in bending with minimum mass

(M = σ_y ^2/3 / ρ).

2.2 A strong circular cross-section beam in bending with minimum cost

(M = σ_y ^2/3 / C_m ρ).

Now perform the following task:

2.3 Determine if there is any overlap between your lists of lightest and cheapest materials from 2.1 and 2.2 respectively (you may need to expand either or both of your shortlists slightly).  Comment on your findings.

Finally, answer the following:

2.4 From a materials selection point of view, how would you use the chart you prepared in task 1.3?  What does it show?

Where appropriate, Copy/Paste all of your CES charts and constructions to support your answers. Again, label and annotate your charts in an appropriate manner.