\section{Algorithmic thinking}\label{algorithmic-thinking} \subsection{Learning Objectives}\label{learning-objectives} By the end of this lesson, students will be able to: \begin{itemize} \tightlist \item Apply algorithmic thinking to solve engineering problems using computational tools. \item Translate engineering problems into structured programming logic. \item Use software tools to implement, test, and refine engineering solutions. \end{itemize} \subsection{Define the Problem}\label{define-the-problem} Like many other classes we need to frame the problem before working it. So before jumping straight into coding or building models, clearly define the engineering problem. \begin{itemize} \tightlist \item \textbf{List knowns and unknowns.} What inputs are given? What outputs are required? \item \textbf{Establish system constraints and assumptions.} Identify physical laws, design requirements, and performance limits. \item \textbf{Clarify computational objectives.} What are you trying to calculate, simulate, or optimize? \end{itemize} \subsection{Think Algorithmically}\label{think-algorithmically} Since we are going to use computers to calculate our solution we first need to break the problem into logical steps that a computer can follow. \begin{itemize} \tightlist \item \textbf{Define the inputs and outputs.} What variables will the program take in, and what results will it produce? \item \textbf{Break the problem into sub-tasks.} Identify steps such as data input, logic processing and output. \item \textbf{Outline the algorithm.} Write pseudocode or flowcharts that describe the computational steps. \item \textbf{Identify patterns or formulas.} Can loops, conditionals, or equations be used to automate parts of the solution? \end{itemize} \textbf{Example:} For processing stress-strain data: 1. Import data from a file. 2. Convert force and displacement to stress and strain. 3. Plot the stress-strain curve. 4. Identify the yield point or modulus. \subsection{Write \& Execute the Code}\label{write-execute-the-code} \begin{itemize} \tightlist \item \textbf{Choose the right tools.} Are there libraries I can use to get to my objective more effectively? \item \textbf{Write modular code.} Use functions to separate different tasks (e.g., reading data, computing values, plotting). \item \textbf{Check for syntax and logic errors.} Debug line-by-line using print statements or a debugger. \end{itemize} \textbf{Example:} Write a Python script that uses NumPy and Matplotlib to load a CSV file, compute stress and strain, and generate plots. \subsection{Test and Validate}\label{test-and-validate} \begin{itemize} \tightlist \item \textbf{Assess the feasibility of your results.} Do the values align with expected physical behavior? \item \textbf{Compare against established benchmarks.} Validate solutions using experimental data, literature values, or known theoretical limits. \item \textbf{Check units and scaling.} Ensure computations are consistent with physical meaning. \end{itemize} \textbf{Example:} If your plot shows stress values in the thousands when you expect hundreds, check unit conversions in your formula. \subsection{Case Study: Simulating a Spring-Mass System}\label{case-study-simulating-a-spring-mass-system} \textbf{Scenario:} Model the motion of a mass-spring-damper system using a numerical solver. \begin{enumerate} \def\labelenumi{\arabic{enumi}.} \tightlist \item \textbf{Define the Problem:} Set up the differential equation from Newton's Second Law. \item \textbf{Develop a Strategy:} Discretize time, apply numerical integration (e.g., Euler or Runge-Kutta). \item \textbf{Execute the Code:} Write a Python function that computes motion over time. \item \textbf{Test the Model:} Compare results with analytical solutions for undamped or lightly damped systems. \item \textbf{Refine the Model:} Add adjustable damping and stiffness parameters. \item \textbf{Troubleshoot Issues:} If the model becomes unstable, reduce the time step or use a more accurate integrator. \end{enumerate}