TY - JOUR
T1 - Response attenuation in a large-scale structure subjected to blast excitation utilizing a system of essentially nonlinear vibration absorbers
AU - Wierschem, Nicholas E.
AU - Hubbard, Sean A.
AU - Luo, Jie
AU - Fahnestock, Larry A.
AU - Spencer, Billie F.
AU - McFarland, D. Michael
AU - Quinn, D. Dane
AU - Vakakis, Alexander F.
AU - Bergman, Lawrence A.
N1 - Funding Information:
This research program was sponsored by the Defense Advanced Research Projects Agency through grant HR0011-10-1-0077 ; Dr. Aaron Lazarus was the program manager. The content of this paper does not necessarily reflect the position or the policy of the Government, and no official endorsement should be inferred. The authors would like to acknowledge the support of US Army Corps of Engineers personnel, in particular Matthew Holmer, during the experimental portions of this research.
PY - 2017/2/17
Y1 - 2017/2/17
N2 - Limiting peak stresses and strains in a structure subjected to high-energy, short-duration transient loadings, such as blasts, is a challenging problem, largely due to the well-known insensitivity of the first few cycles of the structural response to damping. Linear isolation, while a potential solution, requires a very low fundamental natural frequency to be effective, resulting in large nearly-rigid body displacement of the structure, while linear vibration absorbers have little or no effect on the early-time response where relative motions, and thus stresses and strains, are at their highest levels. The problem has become increasingly important in recent years with the expectation of blast-resistance as a design requirement in new construction. In this paper, the problem is examined experimentally and computationally in the context of offset-blast loading applied to a custom-built nine story steel frame structure. A fully-passive response mitigation system consisting of six lightweight, essentially nonlinear vibration absorbers (termed nonlinear energy sinks – NESs) is optimized and deployed on the upper two floors of this structure. Two NESs have vibro-impact nonlinearities and the other four possess smooth but essentially nonlinear stiffnesses. Results of the computational and experimental study demonstrate the efficacy of the proposed passive nonlinear mitigation system to rapidly and efficiently attenuate the global structural response, even at early time (i.e., starting at the first response cycle), thus minimizing the peak demand on the structure. This is achieved by nonlinear redistribution of the blast energy within the modal space through low-to-high energy scattering due to the action of the NESs. The experimental results validate the theoretical predictions.
AB - Limiting peak stresses and strains in a structure subjected to high-energy, short-duration transient loadings, such as blasts, is a challenging problem, largely due to the well-known insensitivity of the first few cycles of the structural response to damping. Linear isolation, while a potential solution, requires a very low fundamental natural frequency to be effective, resulting in large nearly-rigid body displacement of the structure, while linear vibration absorbers have little or no effect on the early-time response where relative motions, and thus stresses and strains, are at their highest levels. The problem has become increasingly important in recent years with the expectation of blast-resistance as a design requirement in new construction. In this paper, the problem is examined experimentally and computationally in the context of offset-blast loading applied to a custom-built nine story steel frame structure. A fully-passive response mitigation system consisting of six lightweight, essentially nonlinear vibration absorbers (termed nonlinear energy sinks – NESs) is optimized and deployed on the upper two floors of this structure. Two NESs have vibro-impact nonlinearities and the other four possess smooth but essentially nonlinear stiffnesses. Results of the computational and experimental study demonstrate the efficacy of the proposed passive nonlinear mitigation system to rapidly and efficiently attenuate the global structural response, even at early time (i.e., starting at the first response cycle), thus minimizing the peak demand on the structure. This is achieved by nonlinear redistribution of the blast energy within the modal space through low-to-high energy scattering due to the action of the NESs. The experimental results validate the theoretical predictions.
KW - Blast mitigation
KW - Modal energy redistribution
KW - Nonlinear energy sink
KW - Passive control
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U2 - 10.1016/j.jsv.2016.11.003
DO - 10.1016/j.jsv.2016.11.003
M3 - Article
AN - SCOPUS:85002887291
VL - 389
SP - 52
EP - 72
JO - Journal of Sound and Vibration
JF - Journal of Sound and Vibration
SN - 0022-460X
ER -