This note deals with three aspects of nonproportional damping in linear damped vibrating systems in which the stiffness and damping matrices are not restricted to being symmetric and positive definite. First, we give results on approximating a general damping matrix by one that commutes with the stiffness matrix when the stiffness matrix is a general diagonalizable matrix, and the damping and s...

Planetary surface vehicles (PSVs) play a critical role in space explorations. Flexible-wheel (FW) suspension concept has been regarded to be one of the novel technologies for future PSVs, where a few experimental studies have demonstrated its potential benefits in improving tractive performance of PSVs. This study develops generalized models for fundamental stiffness and damping properties and ...

0020-7683/$ see front matter 2013 Elsevier Ltd. A http://dx.doi.org/10.1016/j.ijsolstr.2013.03.018 ⇑ Corresponding authors. Tel.: +1 608 346 7275 (L. Don E-mail addresses: [email protected] (L. (R. Lakes). High structural damping combined with high stiffness is achieved by negative stiffness elements. Negative incremental structural stiffness occurs when a column with flat ends is subjecte...

Fluidelastic instability of a single flexible cylinder subject to fluid cross flow has been investigated in arrays of rigid tubes arranged in a normal triangular configuration with pitch ratios of and . The test facility designed and built for this purpose has two novel features: (i) the flexible tube is supported by a linear structure which allows only pure translation of the tube in a directi...

Negative stiffness is understood as the occurrence of a force in the same direction as the imposed deformation. Structures and composites with negative stiffness elements enable a large amplification in damping. It is shown in this work, using an experimental approach, that when a flexible flat-ends column is aligned in a post-buckled condition, a negative structural stiffness and large hystere...

In this article, we present a quantitative stiffness imaging technique and demonstrate its use to directly map the dynamic mechanical properties of materials with nanometer-scale lateral resolution. For the experiments, we use a ‘‘hybrid’’ nanoindenter, coupling depth-sensing nanoindentation with scanning probe imaging capabilities. Force modulation electronics have been added, enhancing instru...

A new fail-safe, variable stiffness, and variable damping isolator (VSDI) device is designed, developed and tested utilizing magneto-rheological elastomers (MREs). This system provides a simultaneous controllable stiffness and damping. The performance of the VSDI is investigated experimentally under dynamic shear loads. The results demonstrate that this VSDI is capable of increase of stiffness ...

This Paper is about landing control of legged robot. Body stiffness and damping is used as landing strategy of a legged robot. First, we only used stiffness control method to control legged robot landing. Second control method,sliding mode controller and feedback linearization controller is applied to enhance position control performance. Through these control algorithm, body center of gravity ...

The Low Yield Strength Steel (LYS) has the superiority over long period of low cycle fatigue, high strain hardening rate and impressive ductility to overcome the local fracture problem existing in regular A36 steel plate. With elastoplastic characteristics and experimental verification, it becomes a good material considered for added damping and stiffness (ADAS) since the stress–strain relation...

Energy dissipators, isolated-resistant and specific structural forms for earthquake resistance are popular topics in the research to improve shock-resistance. In this work, experimental methods were used to investigate the property of low yield strength steel. Carbon content in LYS material is lower than that in other steels; the ultimate stress is three times the yield stress. The ultimate elo...