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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 $\mathrm{MPa}$
$F$ 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 $\mathrm{ }$
$η$ eccentricity parameter $\mathrm{ }$
$λ$ slenderness ratio $\mathrm{ }$
$μ$ 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 $\mathrm{MPa}$