Power and signal cable harnesses on spacecraft are often at 10% of the total mass and can be as much as 30%. These cable harnesses can impact the structural dynamics of spacecraft significantly, specifically by damping the response. Past efforts have looked at how to calculate cable properties and the validation of these cable models on onedimensional beam structures with uniform cable lengths. This paper looks at how to extend that process to twodimensional spacecraftlike panels with nonuniform cable lengths. A shear beam model is used for cable properties. Two methods of calculating the tiedown stiffness are compared. Of particular interest is whether or not handbooks of cable properties can be created ahead of time and applied with confidence. There are three frequency bands in which cable effects can be described. Before any cables become resonant, the cable effects are dominated by mass and static stiffness. After all the cables become resonant, the effect is dominated by increased damping in the structure. In between these two frequency cutoff points, there is a transition zone. The dynamic cable modeling method is validated as a distinct improvement over the lumped-mass characterization of cables commonly used today.
NomenclatureA = cross-sectional area, mm 2 d C = cable diameter, mm E = Young's modulus, MPa E = accumulated root-mean-square response average error, m=s 2 f = frequency, Hz F min , F max = frequency limits for root-mean-square response, Hz f A = axial force per unit length, N=m f T = transverse force per unit length, N=m Gf = frequency response function, m=s 2 =N h B = beam thickness, mm h TC = connector height, mm I, I Eff = area moment of inertia, mm 4 kG = shape factor shear modulus product, MPa k tie = tiedown axial stiffness, N=m k X = axial spring stiffness, N=m k y , k z = transverse spring stiffness, N=m k = rotational spring stiffness, N m=rad L = cable length, mm L RBE2= RBE2 element length, mm t = time, s u = axial deflection, mm v, w = transverse deflection, mm V component = strain energy ratio of component at a given mode x = position, 0 < x < L, mm x 0 = boundary condition position, mm = cross-section angle of rotation, rad f = accumulated root-mean-square response, mm=s , e = structural damping factors , cu = mass density, kg=mm 3