# List of symbols

Symbol | Name of the symbol | Unit |
---|---|---|

$ $ | trapezoidal thread | $\mathrm{ }$ |

$ $ | type of strut mounting | $\mathrm{ }$ |

$C_c$ | coefficient according to load | $\mathrm{ }$ |

$C_t$ | power screw coefficient | $\mathrm{ }$ |

$D_1$ | minor diameter for internal threads | $\mathrm{mm}$ |

$D_4$ | major diameter for internal threads | $\mathrm{mm}$ |

$E$ | Young's modulus | $\mathrm{MPa}$ |

$F_A$ | axial force | $\mathrm{N}$ |

$F_{max}$ | maximal (critical) force | $\mathrm{N}$ |

$H_1$ | height of the overlapping | $\mathrm{mm}$ |

$H_4$ | height of internal threads | $\mathrm{mm}$ |

$I$ | second moment of area | $\mathrm{mm^4}$ |

$L$ | strut length | $\mathrm{mm}$ |

$M_T$ | twisting moment | $\mathrm{Nm}$ |

$M_T$ | lifting torque | $\mathrm{Nm}$ |

$P$ | pitch | $\mathrm{mm}$ |

$P_{B-screw-nut}$ | bearing stress in the screw and nut | $\mathrm{MPa}$ |

$P_{all-B-nut}$ | allowable bearing stress the nut | $\mathrm{MPa}$ |

$P_{all-B-screw}$ | allowable bearing stress the screw | $\mathrm{MPa}$ |

$R_{1max}$ | dimension $ R_{1max} $ | $\mathrm{mm}$ |

$R_{2max}$ | dimension $ R_{2max} $ | $\mathrm{mm}$ |

$S$ | profile area | $\mathrm{mm^2}$ |

$S_F$ | safety factor | $\mathrm{ }$ |

$S_{FB}$ | safety factor buckling | $\mathrm{ }$ |

$S_{y-nut}$ | the minimum yield strength of the nut | $\mathrm{MPa}$ |

$S_{y-screw}$ | the minimum yield strength of the screw | $\mathrm{MPa}$ |

$a_c$ | clearance on the crest | $\mathrm{mm}$ |

$c$ | extreme fiber distance | $\mathrm{mm}$ |

$d$ | major diameter for external thread (nominal diameter) | $\mathrm{mm}$ |

$d_2$ | pitch diameter for external threads | $\mathrm{mm}$ |

$d_3$ | minor diameter for external threads | $\mathrm{mm}$ |

$e$ | eccentricity | $\mathrm{mm}$ |

$h_3$ | height of external threads | $\mathrm{mm}$ |

$i$ | gyration radius | $\mathrm{mm}$ |

$l$ | length nut | $\mathrm{mm}$ |

$n$ | speed | $\mathrm{rpm}$ |

$v$ | screw speed | $\mathrm{m/s}$ |

$z$ | dimension $ z $ | $\mathrm{mm}$ |

$β$ | coefficient for buckling | $\mathrm{ }$ |

$μ$ | friction coefficient | $\mathrm{ }$ |

$σ_{A-screw}$ | axial stress in the screw | $\mathrm{MPa}$ |

$σ_{all-A-screw}$ | allowable axial stress the screw | $\mathrm{MPa}$ |

$σ_{all-C-screw}$ | allowable combined stress the screw | $\mathrm{MPa}$ |

$σ_{tresca-screw}$ | combined stress in the screw | $\mathrm{MPa}$ |

$τ_{S-screw}$ | shear stress in the screw | $\mathrm{MPa}$ |

$τ_{all-S-screw}$ | allowable shear stress the screw | $\mathrm{MPa}$ |