CALCS | BAS021 FATIGUE LOAD COMBINATIONS |

## NOTATION | |

CC | combined case id, component of load group |

flg | stress, load group, at stress recovery point |

fij | stress, for unit acceleration factor (i), stress recovery point (j) |

Kmi | acceleration factor, mean, for acceleration component (i) |

Kij | acceleration factor, combined case, for unit acceleration (i), stress recovery point (j) |

LG | load group id |

Nuc | No.unit cases |

Nlg | No.load groups |

SRP | stress recovery point |

Maximum numbers of: Nuc 10, Nuc*Nsrp 1000, Nuc*Ncc 1000

Stress cycle ranges are segregated into groups. Note that the following equality must exist in the input data, Loads/group = Ncc/Nlg

Stress at a point is a function of any number of unit accelerations, for example these may be loads parallel to the structure global x y & z axes.

Any number of unit cases may be defined, program maximun dimension is presently set to ten.

Stresses for combined load cases are derived as,

flgj = f1j.k1j + f2j.k2j + f3j.k3j...+fnj.knj

Stresses are calculated using combined case factors as follows, noting that gravity 1g may be accounted for by setting the appropriate value of km (mean acceleration factor) to 1.00,

fj.(kmj +- kij)

## INPUT FORMAT | |||||||||

DAT021 | title | ||||||||

data | Nuc | ||||||||

data | Nlg | ||||||||

SRP | fu1 | fu2 | etc | ||||||

enter | tab | delimited | data | ||||||

CC | K1 | K2 | etc | ||||||

enter | tab | delimited | data | ||||||

ENDDAT | |||||||||

## EXAMPLE | |||||||||

## Input | |||||||||

DAT021 | example | ||||||||

3 | Nuc | ||||||||

2 | Nlg | ||||||||

SRP | fu1 | fu2 | fu3 | ||||||

0. | 0. | 1. | 0. | ||||||

4 | .7 | -108.9 | 4.5 | ||||||

1002 | 105.7 | 57.46 | 237.8 | ||||||

CC | K1 | K2 | K3 | ||||||

1 | 0 | 1.002 | .001 | ||||||

2 | .003 | 1.01 | 0 | ||||||

3 | .002 | 1.005 | 0 | ||||||

4 | 0 | 1.017 | .07 | ||||||

5 | .049 | 1.115 | 0 | ||||||

6 | .034 | 1.069 | .049 | ||||||

ENDDAT | |||||||||

## Output | |||||||||

SRP | flg1 | flg2 | |||||||

4max | -107.81 | -96.342 | |||||||

..min | -109.99 | -121.46 | |||||||

..range | 2.1822 | 25.116 | |||||||

..mean | -108.9 | -108.9 | |||||||

1002max | 58.352 | 76.671 | |||||||

..min | 56.568 | 38.249 | |||||||

..range | 1.7834 | 38.421 | |||||||

..mean | 57.46 | 57.46 | |||||||

END021 |