# Chapter 10: Projects

The projects section of this text is intended to provide examples that are summative and encompass many topics covered within this text. Each exercise is currently provided in several versions with different levels of prerequisite knowledge. These exercises may be used as homework assignments, as a basis for more complex assigned projects, or as ways for independent students to verify that they are able to apply individual skills addressed previously to solve a complex and, hopefully, applicable process.

## Contents in Projects Section:

• Elastic modulus calculation (in three versions)
• Unit conversion calculations (in two versions)
• Material density scenarios (one version)

## Project 1: Elastic Modulus Calculation

The elastic modulus of a material measures a material’s resistance to being deformed elastically. Useful in materials analysis, the elastic modulus is frequently calculated from data collected from mechanical testing of materials. The following projects have the user generate forms of elastic modulus calculators which input a variety of data types depending on the complexity of the version.

### Project 1 Version 1: Elastic Modulus Calculator

Concepts: Use scripts with inputs to determine the elastic modulus, stress, and strain of material.

Problem: A team of engineers is conducting tensile tests on plastics that will be used in a car part and need to determine the materials elastic modulus, or E. Elastic modulus is a ratio of the stress exerted on a material (σ) over the material’s strain (ϵ), which can be further expressed by the following equation, where F is the force applied to the material,  A is the material’s cross-section, L is the materials initial length, and ΔL is the change in the length of the material after the test (or the final length – the initial length).

$E=\sigma/\epsilon=(F/A)/(\Delta L/ L_i\ )$

Create a MATLAB script that enables engineers to input values for each variable and will calculate the elastic modulus.

### Project 1 Version 2: Elastic Modulus Calculator

Concepts: Require students to input data and export data to determine the elastic modulus, stress, and strain of material.

Problem: A team of engineers is conducting tensile tests on plastics that may be used in a car part and need to determine the materials elastic modulus, or E. Elastic modulus is a function of the stress on a material (σ) over the material’s strain (ϵ), which can be further expressed by the following equation, where F is the force applied to the material,  A is the material’s cross-section, L is the materials initial length, and ΔL is the change in the material’s length after the test (or the final length – the initial length).

$E=\sigma/\epsilon=(F/A)/(\Delta L/ L_i\ )$

Create a MATLAB script that enables engineers to input an excel sheet provided by your instructor containing data for each variable and will output the corresponding elastic modulus onto the excel sheet.

### Problem 1 Version 3: Elastic Modulus Calculator

Concept: Determine the stress and strain values independently and graph the resulting stress/strain curve.

Problem: A team of engineers is conducting tensile tests on plastics that may be used in a car part and need to determine the materials elastic modulus, or E. Elastic modulus is a function of the stress on a material (σ) over the material’s strain (ϵ), which can be further expressed by the following equation, where F is the force applied to the material,  A is the material’s cross-section, L is the materials initial length, and ΔL is the change in the length of the material after the test (or the final length – the initial length).

$E=\sigma/\epsilon=(F/A)/(\Delta L/ L_i\ )$

Refer to your instructor for a data set. Create a code that can create a graph plotting stress data on the Y-axis and strain data on the X-axis. Create labels and a title for the graph.

## Project 2: Unit Conversion Calculator.

This set of problems has the user generate codes capable of converting between Standard International and US Customary system units. This operation can be modified to have the user generate graphical user interfaces and more conversion options, requiring a variety of skills addressed within the body of the text.

### Project 2 Version 1: Unit Conversion Calculator.

Concept: Write a script to complete a mathematical computation converting units.

Problem: Engineers frequently convert between US customary distances and SI distances when working on projects. To speed up the job of a construction engineer, create a MATLAB code that can convert miles to feet and to meters. There are 5280 feet in a mile and 1609.3 meters in a mile.

### Project 2 Version 2: Unit Conversion Calculator

Concept: Write a script using a graphical user interface and an if statement to complete mathematical unit conversions.

Problem: Engineers frequently convert between US customary distances and SI distances when working on projects. To speed up the job of a construction engineer, create a unit conversion script that can convert from either feet, miles, or meters and output lengths in terms of the other two units. Do so using a graphical user interface. There are 5280 feet in a mile and 1609.3 meters in a mile.

## Project 3: Material Density Scenarios

### Project 3 Version 1: Material Density Scenarios

Concept: Calculate the Density of Various Materials using a graphical user interface.

Problem: You are a mechanical engineer working with several polymer composite materials. Each of these materials has different densities. To save time, you would like a code that can calculate the total mass and gravitational force on a given polymer material with a given volume. Create a code that can select between the following materials, prompt the user to input a volume, and output the total mass of the material.

• Low Density Polyethylene (LDPE): 920  kg/m^3
• High Density Polyethylene (HDPE):  950  kg/m^3
• High Impact Polystyrene (HIPS): 1050  kg/m^3
• 80% Polypropylene + 20% Glass Fiber Composite (PP+GF): 1114  kg/m^3