LOADCYH

Bulk Data Entry Used to define the loading by harmonics in cyclic symmetry analysis.

Format

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
LOADCYH SID S HID HTYPE S1 L1 S2 L2
+ S3 L3 etc.

Example

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
LOADCYH 12 1.0 11 C 2.5 23 1.0 11

Definitions

Field Contents SI Unit Example
SID Load identification number.

No default (Integer > 0)

S Scale factor. 7

No default (Real)

HID Harmonic index. 3

This entry is valid only when HTYPE = C or S.

No default (Integer ≥ 0)

HTYPE Flag for the harmonic type. 4 5
blank (Default)
The load will be applied to both C and S components.
GRAV
Gravity loading.
RFORCE
Centrifugal loading.
C
Coefficient of Cosine components of harmonics specified through HID.
S
Coefficient of Sine components of harmonics specified through HID.

(Character or blank)

Si Scale factor. 7

No default (Real)

Li Load identification number.

May reference any of the loading entries, except accelerations (ACCEL/ACCEL1/ACCEL2).

No default (Integer > 0)

Comments

  1. LOADCYH Bulk Data Entry can be referenced by LOAD in the Subcase Information section.
  2. LOADCYH can share a same ID with other LOADCYN or LOADCYH Bulk Data Entries.
  3. LOADCYH cannot share a same ID with other load set bulk entries. The harmonic index HID should be also specified by HARMONICS, and are supposed to be non-negative and must be no greater than (NSEG is defined in the CYSYM Bulk Data Entry).

    If NSEG is odd:

    (NSEG12)

    If NSEG is even:

    (NSEG2)

  4. When, HTYPE = GRAV and RFORCE, the loading refers to GRAV and RFORCE entries, respectively. In these cases, HID is not required since the harmonic loads for appropriate available harmonics (also specified by HARMONICS) will be generated automatically.
  5. An arbitrary load {F(j)} applied to the jth segment of the structure (through LOADCYN) can be decomposed as:
    {F(j)}=l[{Fl}cos2πl(j1)NSEG+{ˉFl}sin2πl(j1)NSEG]

    Where, l is the harmonic index (HID).

    HTYPE = C or S are load options that directly specify the above coefficients {Fl} and {ˉFl} of the lth harmonic, for the cosine and sine components, respectively.

    If HTYPE is blank, the load will be applied to both C and S components.

  6. LOADCYN can reference all types of loads including an SPCD that defines enforced displacement, velocity or acceleration values. The LOADADD Bulk Data Entry is not supported.
  7. The loading defined by LOADCYN is given by:
    P=S(Ni=1SiPLi)
    Where,
    PLi
    Load vector referenced through Li.
    N
    Number of load vectors.
  8. In cyclic symmetry analysis, the specified coordinate system (CID field) on GRAV must be rectangular. The component parallel to the axis of cyclic symmetry would contribute to the zeroth harmonic and the components perpendicular to the axis would contribute to harmonic of the first order.
  9. In cyclic symmetry analysis, the rotational vector of RFORCE must coincide with the axis of symmetry which results in a cyclic symmetric centrifugal loading.
  10. Nonlinear implicit cyclic symmetry subcases do not allow non-cyclic symmetric loadings and behaviors due to theoretical restrictions. Therefore, the regular method of loadset definition is adopted, that is, to directly reference a loadset ID of either load collectors LOAD(ADD)/DLOAD or a set of loads.