Stiffness 20 Finite element method 7 Backward differentiation formulae 5 Numerical results 5 Bolted joints 4 Bolts 4 Concretes 4 Deformation 4 Experimental modal analysis 4 Mechanical properties 4 Modal analysis 4 Numerical methods 4 Ordinary differential equations 4 Reinforced concrete 4 Seismology 4 Stiff ordinary differential equations 4 stiffness 4 Asphalt 3 Asphalt mixtures 3 Concrete buildings 3 Cyclic loads 3 Damping 3 Earthquake engineering 3 Energy dissipation 3 Initial value problems 3 Natural frequencies and modes 3 Strength and stiffness 3 ductility 3 stiff 3 ABAQUS 2