| Girty, 
      G. 2002. Strain Machine, A Macromedia Director 
      8.5 Application for Introducing the Concepts of 
      Simple and Pure Shear. In: Bobyarchick, A. 2002. 
      Visualisation, Teaching and Learning in Structural 
      Geology. Journal of the Virtual Explorer, 9, 31-38. 
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       Strain 
        Machine 
        A Macromedia Director 8.5 Application for Introducing  
        the Concepts of Simple and Pure Shear 
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          | Figure 8. 
            Vector-displacement maps based on 7 strain increments with (e+1) 
            = 1.1 and γ = 0.3. (A) Pure shear. (B) Simple shear. Click on the 
            Show Initial Circle and Strain Ellipse button to gain access to animations 
            of particle displacement paths.  Note the different paths that 
            particles travel as they are displaced from their positions on the 
            circumference of the circle to their positions on the strain ellipse. | 
         
       
       
      
           
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            | Figure 9.  
              To observe the positions of lines of no finite longitudinal strain 
              during seven increments of pure shear slide the silver ring to the 
              right or click on the Play Movie button. Note that during the experiment 
              that the X and Z principal strain axes lengthened and shortened, 
              but otherwise remained stationary. Any material line whose orientation 
              lies with the pie-shaped segment bisected by Z has been shortened 
              while those with orientations lying within the pie-shaped segment 
              bisected by X have been lengthened. | 
           
         
         
        
           
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            | Figure 10. 
              To observe the positions of lines of no finite longitudinal strain 
              during  seven increments of simple shear slide the silver ring 
              to the right or click on the Play Movie button. Note that the X 
              and Z principal strain axes have rotated toward the direction of 
              shear while one line of no finite longitudinal strain lies unchanged 
              and parallel to the x-coordinate axis, i.e., the direction of shear. 
              As with figure 9 any material line whose orientation lies with the 
              pie-shaped segment bisected by Z has been shortened while those 
              with orientations lying within the pie-shaped segment bisected by 
              X have been lengthened. | 
           
         
          
       
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