Support Topics
Support Topics / Engineer's Studio(R)
Placement of soil spring on plate element

　In the beginning
When the total ground structure is modeled, there are the cases that ground resists when the structure touches ground and that you want to model the action that ground doesn't resist when they are apart. Spring element is used in this case. However because there are quite a lot of nodes of plate element, it takes a lot of effort for placement of appropriate spring element for each node position. Engineer's Studio(R) has a function which arranges a spring element to plate element automatically.
By only inputting parameter of stratum characteristic, the program calculates the area divided by spring element on node position and each rigidity of spring characteristic, and that would be very useful.
Here is the introduction of input procedure and the example of result below.
　Input
  1. Stratum characteristic is created. (Figure 1) Stratum characteristic is 3 parameters of layer thickness, modulus of subgrade reaction ([kN/m3]) and maximum subgrade reaction intensity ([kN/m2]). Every one of these is ground coefficient which is used often.
    Figure 1　Input of stratum characteristic

  2. Make zl axis of plate element of side surface and bottom surface face outward. (Figure 2)。
    Figure 2　Direction of zl axis of plate element

  3. Click 4 side walls. Plate element becomes selective state.

  4. Ribbon "Model｜Edit｜Soil spring". (Figure 3)。

    Figure 3　Ribbon "Model｜Edit｜Soil spring"

  5. Input the setting screen of Figure 4. The direction of spring element specifies "forward direction" and coordinate system yl vector specifies "whole Y".

    Figure 4　Setting screen of soil spring

  6. Click bottomslab. Plate element becomes selective state.

  7. Click ribbon "Model｜Edit｜Soil spring". (Figure 3)。

  8. Input the setting screen of figure 4. Set the direction of spring element to "Forward direction" and coordinate system yl vector to "Arbitrary setting", and set (Vx,Vy,Vz)=(1,0,0) as well.

  9. Soil spring is automatically created like figure 5.

Figure 5　Soil spring created automatically

　Result
Figure 6 is element coordinate system of spring element. xl axis of spring element is facing outward.
Txl of spring characteristic becomes the spring that the soil resists. Figure 7 is a spring characteristic created automatically. Spring characteristic always becomes a negative direction bilinear. Each value of spring characteristic is calculated automatically from stratum characteristic and plate element.

Figure 6　Element coordinate system of spring element  Figure 7　Spring characteristic created automatically
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