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FEM 

GEO5

Geotechnical software

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Coordinate systems

Global coordinate system

- is right-handed
- the positive X axis is directed from the left to the right
- the positive Z axis is directed from the bottom to the top
- the positive Y axis drills in to the XZ plane
- the rotation about the Y axis is positive when measured clockwise
- The GCS is used for coordinates
- in general, the positive surcharge is assumed to act in the opposite direction to the positive axis and the positive rotation follows the positive sense of the global rotation
- particular definitions of the positive direction must be carefully examined for all cases


Surcharge

- is always assumed to act along the horizontal line (or at a point)
- the origin (point) and the length are the required input data
- the positive surcharge at zero angle is assumed to act in the opposite direction to the positive direction of the Z axis
- the zero angle corresponds to vertical surcharge
- the angle increases clockwise
- the angle ranges from -180º to 180º



Anchors

- an anchor can also be specified by the origin and an angle
- the zero angle corresponds to the direction of the X axis
- the angle increases clockwise
- the angle ranges from -180º to 180º


Prescribed displacements and rotation of supports

- prescribed displacements are positive in the directions of the X, Z axes and about the Y axis
- displacements are positive when developed in the opposite direction to the positive directions of the coordinate axes
- the positive rotation is measured clockwise


Load of beams

- the local coordinate system is right-handed
- the positive XL axis of the beam is assumed in direction from the starting to the end point
- the positive ZL axis is perpendicular and rotated counterclockwise by 90º from the beam axis
- loading can be applied three directions:
- global Z
- global X
- local normal (Z)
- the positive loading in the global direction acts in the opposite direction to the positive direction of the corresponding axis
- the positive loading in the normal direction acts in the opposite direction to the positive direction of the local ZL axis
- the positive loading angle α is measured clockwise
- the moment is positive when acting clockwise
- definition of loading along the XL axis
- coordinates, coordinates of the origin
- loading span
- types of loading (always in above mentioned directions)
- concentrated force
- concentrated moment
- distributed uniform over the whole beam
- distributed trapezoidal over the whole beam
- distributed uniform over a segment of the beam
- distributed trapezoidal over a segment of the beam


Stresses and strains

- positive normal stress Sigma corresponds to compression, negative to tension
- positive normal strain Epsilon corresponds to compression, negative to tension


Internal forces along beams

- positive normal force corresponds to tension, negative to compression
- positive normal strain Epsilon corresponds to compression, negative to tension

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