updated hw4 2024

Author: antantantant

_posts/teaching/mechdesign/2023-03-20-homework3solution.md

@@ -2,7 +2,7 @@
 categories: mechdesign_homework
 layout: mechdesign_default
 title:  Homework 3 Solution
-published: false
+published: true
 ---
 
 For problems 1-5, see [solutions](/_teaching/mechdesign/Homework/Homework 3 Solutions 2023.pdf).

_posts/teaching/mechdesign/2023-03-21-homework4.md

@@ -57,18 +57,16 @@ If infinite life is not predicted, estimate the number of cycles to failure.
 <img src="/_images/mechdesign/hw3_1.png" alt="Drawing" style="height: 400px;"/> 
 
 ### Problem 4 (50 Points)
-Choose one of the following two problems.
+First, complete [this tutorial](https://courses.ansys.com/index.php/courses/plate-with-a-hole-optimization/lessons/problem-specification-lesson-1-30/) to get familiar with structure design in ANSYS. 
+For more explanations on ANSYS Optimization, please check [this tutorial](https://designinformaticslab.github.io/productdesign_tutorial/2016/11/20/ansys.html).
 
-![Alt text](https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2Fwww.teslaoracle.com%2Fwp-content%2Fuploads%2F2022%2F06%2FSpaceX-Starship-Launch-Tower-Chopsticks-Starbase-1024x576.jpg&f=1&nofb=1&ipt=6d694dfa53f339a5607fc517dfea56191940cc7ad0bd3d2b846841cb440a8d4d&ipo=images "a title")
+Then choose one of the following structure design problems to solve using ANSYS.
+1. The "Chopsticks" that catch SpaceX BFRs during their landing.
+2. A bridge. To narrow down the design specifications, you could refer to any famous bridges, e.g., the Mathematical Bridge at Cambridge. 
 
-1. "Chopsticks" (see figure below) is introduced to facilitate the landing of SpaceX BFRs. 
-To design the chopsticks concept, let us simplify it as a 2D truss structure and consider the rocket as a point load 
-(similar to what we did in the design competition).
-    * (40 Points) Derive an optimal truss design that minimizes the compliance while satisfying a total weight constraint.
-    * (10 Points) For the design you created, comment on its yield, fatigue, and buckling risks.
+For the problem of your choice: 
+* (10 Points) Clearly explain your design objectives, variables, constraints, and assumptions.
+* (40 Points) Find and validate the optimal design.
+   
 
-    This [truss optimization code](https://colab.research.google.com/drive/102Bu4ZGRkomLlhbVwEtHPjyIJEPSGE_e#scrollTo=ZNYHR-rbkv5a) may come in handy. 
 
-2. Follow [this tutorial](https://courses.ansys.com/index.php/courses/plate-with-a-hole-optimization/lessons/problem-specification-lesson-1-30/) to solve a structure design problem in ANSYS. 
-Please note that you can either use the running example in the tutorial, or define your own design problem.
-For more explanations on DOE and Optimization options, please check [this tutorial](https://designinformaticslab.github.io/productdesign_tutorial/2016/11/20/ansys.html).