
Math General Math Forum  For general math related discussion and news 
 LinkBack  Thread Tools  Display Modes 
October 16th, 2018, 11:09 AM  #1 
Member Joined: Feb 2018 From: England Posts: 61 Thanks: 0  Merit Index.
Hi All, Really struggling with the following question, been trying to research to no avail! Any help would be much appreciated. Function: To support a hanging load Constraints: Minimise cost cap C Objectives: Must carry load without failure, σ ≤ σ y ; Length L Free variables: Crosssectional area A ; Material used i. The objective is to minimise the actual cost C of the support rod. However, the material supplier can only provide the price per unit volume Pv of the material chosen. Show that the objective equation is given C = PvAL. Note: To answer this question you will need to derive an equation linking the actual cost of the material used to the price per unit volume provided by the supplier. Include the equation with all your workings in your answer. ii. Derive an equation defining the strength constraint. Include the equation with all your workings in your answer. iii. By combining the objective and constraint equations to eliminate the free variables, show that the final combined equation is C = Pv FL / σ y. Include the equation with all your workings in your answer. iv. Separate the variables of the combined equation into functional F, geometric G and materials M groupings. In your answer, show the combined equation clearly identifying the F, G and M groupings. v. In your answer, show the merit index you derived for this problem is Pv / σ y. Define the axes you would adopt on an Ashby chart to be able to use your merit index and state, with a reason, whether the merit index should be maximised or minimised. Thank you. 

Tags 
index, merit 
Thread Tools  
Display Modes  

Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
Del index notation  henrymerrild  Calculus  0  March 6th, 2015 03:07 AM 
Composite index  jiasyuen  Algebra  1  March 1st, 2014 09:16 AM 
search index  sigma123  Linear Algebra  0  August 7th, 2012 01:53 AM 
Gittins index  sangoh  Applied Math  0  April 29th, 2009 09:28 PM 
composite index  jamil  Algebra  0  December 2nd, 2007 04:33 AM 