March 19th, 2012, 01:09 PM  #1 
Newbie Joined: Mar 2012 Posts: 1 Thanks: 0  3d Matrix problem
Hello, Can anyone help me solving the following math/physics problem. The problem should be solved with a matrix. An architect wants to decorate a building by using open cubes, with a diagnal stand compare the body vertical diagonal, between the pillars. The diameter of all bars is the same: A = 400mm2 steel: E = 200 kN = mm2. The length of the ribs, a = 1m. The rotational stiffness of the vertices of the cube can be neglected. Therefore, the rigidity cube retrieves from among the eight plane diagonals, also with surface area of ??the crosssection of: Ad = 400mm2, and of a length of P2A. The tilting of the cube is not considered. The cube is vertically loaded (Force direction 0,0,0 to 1,1,1) 1. What is the efective rigidity of the cube? Or when it is loaded with a vertical force Fz what is the vertical displacement z? 2. Now the architect the thick plane diagonals not so beautiful and she wants thinner than the original Ad = 400mm2. Derive a formula for the stiffness of the cube as a function of The surface area Ad of the cross section of the surface diagonals. I couldn't add a picture of the cube. I hope the coordinates help. bar/diagonal, P1,P2, X, Y, Z, X,YZ V1 A D 0 0 0 1 0 0 V2 A B 0 0 0 0 1 0 V3 A W 0 0 0 0 0 1 S1 D B 1 0 0 0 1 0 S2 B W 0 1 0 0 0 1 S3 D W 1 0 0 0 0 1 W1 B C 0 1 0 1 1 0 W2 C D 1 1 0 1 0 0 W3 D T 1 0 0 1 0 1 V1' V U 1 1 1 0 1 1 V2' V T 1 1 1 1 0 1 V3' V C 1 1 1 1 1 0 S1' C U 1 1 0 0 1 1 S2' T U 1 0 1 0 1 1 S3' T C 1 0 1 1 1 0 W1' T W 1 0 1 0 0 1 W2' W U 0 0 1 0 1 1 W3' U B 0 1 1 0 1 0 

Tags 
matrix, problem 
Thread Tools  
Display Modes  

Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
Matrix  problem  gadmich  Linear Algebra  2  June 11th, 2013 02:23 AM 
Help: matrix problem  tweedle  Linear Algebra  1  June 4th, 2012 10:27 PM 
Matrix Problem  knowledgegain  Linear Algebra  3  April 29th, 2009 05:49 AM 
Matrix problem  jlfr  Linear Algebra  2  March 30th, 2008 07:02 PM 
Matrix problem...help..help..  rere  Linear Algebra  1  March 20th, 2008 03:47 AM 