Example 412: Analysis of a bicycle using truss elements

This problem investigates the loading of a bicycle frame. The bicycle frame is modelled with truss elements.


The comfile run by this example is as follows:

#Example_412 A bicycle truss problem                               
                                                                       
fem                            #Set up the FEM environment              
fem define nodes;r;bicycle;example #Read the bicycle nodes
fem define window;c            #Calculate the window size              
fem define bases;r;;example    #Defines a linear basis function
fem define elements;r;;example #Defines bicycle elements   
fem define fibre;d                   #Default fibre angle (these need to be 
fem define elements;r;;example fibre #done but add no new information)
fem draw lines                 #Make the line segments visible          
fem draw nodes                 #Make the node numbers visible           
fem define equation;p          #Define a static analysis using 
#                                linear elasticity with truss 
#                                elements for elements 1..6. The
#                                basis function for the u and v
#                                displacements is 1. Default all
#                                other options.
fem define material;p          #Define the material parameters. Define 
#                                an isotropic material with a Young's 
#                                modulus of 70 GPa (Aluminium), and a
#                                cross-area of 5 cm^2. Default all 
#                                other options. Note: density is not 
#                                a required input. (for Aluminium it is 
#                                2700 kg/m^3).
fem define initial;p           #Define initial and boundary conditions 
#                                for the problem. Consider the case
#                                of a person sitting on the bicycle
#                                giving a downwards force of 1 kN
#                                at the seat. Fix the displacements
#                                of nodes 1 and 5 in both the x and 
#                                y directions (so the problem becomes
#                                statically determinant) and apply
#                                a downwards integrated force of 1 kN 
#                                at node 3, i.e. the force vector is
#                                (0.0,-1.0) kN.
#                                NOTE: If Young's modulus is entered
#                                in GPa then the units of force are
#                                kN and the units of displacement
#                                are um (micrometers).
fem define solve;p            #Define the solver options. Default all
#                                options.
fem solve                      #Solves the boundary value problem
fem draw line deformed dotted scale 50 #Draws (scaled) deformed 
#                                bicycle with dotted lines 
fem list node solution         #List the nodal displacements 
fem list node reaction         #List the nodal reactions (forces) 
fem list stress                #List the element stresses         
fem draw reaction scale 2      #Draw (scaled) reaction (force) vectors 

Files used by this example are:

Name             Modified     Size

example_412.com 20-Feb-2004 3.1k bicycle.ipbase 10-Apr-2000 893 bicycle.ipelem 10-Apr-2000 1.6k bicycle.ipelfb 10-Apr-2000 890 bicycle.ipequa 26-May-2003 1.8k bicycle.ipinit 10-Apr-2000 687 bicycle.ipmate 10-Apr-2000 805 bicycle.ipnode 10-Apr-2000 994 bicycle.ipsolv 13-Apr-2007 1.1k

Download the entire example:

Name                      Modified     Size

examples_4_41_412.tar.gz 14-Apr-2007 4.4k

Html last generated: Sun Mar 6 05:50:20 2016

Input last modified: Fri Apr 13 10:33:04 2007


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