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CELAS2 |
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CELAS2 |
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CELAS2 |
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CELAS2 |
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Bulk Data Entry
CELAS2 – Scalar Spring Property and Connection
Description
Defines a scalar spring element of the structural model without reference to a property entry.
Format
(1) |
(2) |
(3) |
(4) |
(5) |
(6) |
(7) |
(8) |
(9) |
(10) |
CELAS2 |
EID |
K |
G1 |
C1 |
G2 |
C2 |
GE |
S |
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Field |
Contents |
EID |
Unique element identification number. No default (Integer > 0) |
K |
Spring stiffness. No default (Real) |
G1, G2 |
Geometric grid point or scalar point identification number. Default = 0 (Integer > 0) |
C1, C2 |
Component number in the displacement coordinate system specified by the CD entry of the GRID data. Default = 0 (0 < Integer < 6) |
GE |
Damping coefficient. GE is ignored in transient analysis, if PARAM, W4 is not specified. Default = 0.0 (Real) |
S |
Stress coefficient. Default = 0.0 (Real) |
| 1. | Zero or blank may be used to indicate a grounded terminal G1 or G2 with a corresponding blank or zero C1 or C2. A grounded terminal is a point whose displacement is constrained to zero. |
| 2. | Scalar points may be used for G1 and/or G2 (with a corresponding C1 and/or C2 of zero or blank). If only scalar points and/or grounded terminals are involved, it is more efficient to use the CELAS4 entry. |
| 3. | This single entry completely defines the element since no material or geometric properties are required. |
| 4. | The two connection points (G1, C1) and (G2, C2) must be distinct. |
| 5. | To obtain the damping coefficient GE, multiply the critical damping ratio, C/C0, by 2. |
| 6. | A scalar point specified on this entry need not be defined on an SPOINT entry. |
| 7. | The element force of a spring is calculated from the equation: F = k * (u1 – u2) |
Where, k is the stiffness coefficient for the scalar element and u1 is the displacement of the first degree-of-freedom listed on the CELAS entry. Element stresses are calculated from the equation: s = S * F, where, S is the stress coefficient as defined above.
| 8. | When the SPSYNTAX setting on the SYSSETTING I/O option is set to CHECK (default) or STRICT, it is required for grid/component pairs (G#/C#) that the component be 0 or blank when the grid reference is a scalar point (SPOINT), and that the component be > 1 when the grid reference is a structural grid point (GRID). When SPSYNTAX is set to MIXED, it is allowed for grid/component pairs (G#/C#) that the grid reference be either a scalar point (SPOINT) or a structural grid point (GRID) when the component is 0, 1 or blank; interpreting all of these as 0 for scalar points and as 1 for structural grids. When the component is greater than 1, the grid reference must always be a structural grid (GRID). |
| 9. | A CBUSH element, referencing a PBUSH property with a single stiffness term, is equivalent to a CELAS1 or CELAS2 element, only when the elements have zero length. A non-zero length CBUSH assumes rigid body connections from the connection points, GA and GB, to the spring-damper location, as defined either by S or the OCID and Si fields. |
| 10. | This card is represented as a spring or mass element in HyperMesh. |
