Handbook on dynamics of jointed structures.

Abstract

The problem of understanding and modeling the complicated physics underlying the action and response of the interfaces in typical structures under dynamic loading conditions has occupied researchers for many decades. This handbook presents an integrated approach to the goal of dynamic modeling of typical jointed structures, beginning with a mathematical assessment of experimental or simulation data, development of constitutive models to account for load histories to deformation, establishment of kinematic models coupling to the continuum models, and application of finite element analysis leading to dynamic structural simulation. In addition, formulations are discussed to mitigate the very short simulation time steps that appear to be required in numerical simulation for problems such as this. This handbook satisfies the commitment to DOE that Sandia will develop the technical content and write a Joints Handbook. The content will include: (1) Methods for characterizing the nonlinear stiffness and energy dissipation for typical joints used in mechanical systems and components. (2) The methodology will include practical guidance on experiments, and reduced order models that can be used to characterize joint behavior. (3) Examples for typical bolted and screw joints will be provided. 3 AcknowledgmentThe authors thank the many managers and members of technical staff who have worked on this challenging problem at various times since its inception. For all of them, this involved a tremendous amount of hard work and for our management team it involved taking a substantial risk. To put significant resources year-after-year into a problem that had so successfully resisted the best efforts of the scientific community can be a gutsy decision on the part of manager. The authors believe that we have justified our managers' faith in us.Among the managers who should be recognized are

Nonlinear Variability due to Mode Coupling in a Bolted Benchmark Structure

“…DP4 is omitted since it did not produce a high enough Mode 1 amplitude. The damping for Mode 1 decreases with increasing amplitude, which is the opposite of what one would expect for a microslip joint nonlinearity [9], suggesting the nonlinearity in this mode is dominated by something other than microslip.…”

An experimental approach on energy dissipation of bolted joints using a modified oscillator device

“…Complex structures in engineering practice are commonly assembled by a large number of jointing components. Recent investigations (Ames et al, 2009; Gaul and Schmidt, 2019; Xiao et al, 2014) have shown that micro- and macro-slipping will occur on contact interfaces of jointing components under external loads. These phenomena are responsible for nonlinear contact stiffness and structural damping (Bograd et al, 2011; Gaul and Nitsche, 2001).…”

“…Identification of Iwan model depends on precise experimental data of jointed structures. Quasi-static experimental investigations (Ames et al, 2009; Eriten et al, 2012; Resor and Starr, 2008; Xu et al, 2020) indicate a weak nonlinearity of contact stiffness during micro-slip stage, which is relatively difficult to capture. Therefore, measuring joint damping through dynamic experiments is often considered.…”

An adaptive component mode synthesis method for dynamic analysis of jointed structure with contact friction interfaces

“…To obtain the dynamical response for nonlinear joint models, this would require iterative solvers. Most existing mod-elling approaches including the non-linear contact friction models employ either time domain solvers [7] (e.g.Runge-Kutta or Newmark method [8]) or frequency domain solvers [6,9] (e.g.harmonic balance methods (HBM)). To solve the full scale jointed model without reduction for a wide range of frequencies or time, the computational expense with these solvers is usually unacceptable.…”