This paper studies uncoupled poroelastic (flow-dependent) and intrinsic viscoelastic (flow-independent) energy dissipation mechanisms via their dependence on characteristic lengths to understand the root of cartilage's broadband dissipation behavior. Phase shift and dynamic modulus were measured from dynamic microindentation tests conducted on hydrated cartilage at different contact radii, as well as on dehydrated cartilage. Cartilage weight and thickness were recorded during dehydration. Phase shifts revealed poroelastic- and viscoelastic-dominant dissipation regimes in hydrated cartilage. Specifically, phase shift at a relatively small radius was governed by poroviscoelasticity, while phase shift at a relatively large radius was dominantly governed by intrinsic viscoelasticity. The uncoupled dissipation mechanisms demonstrated that intrinsic viscoelastic dissipation provided sustained broadband dissipation for all length scales, and additional poroelastic dissipation increased total dissipation at small length scales. Dehydration decreased intrinsic viscoelastic dissipation of cartilage. The findings demonstrated a possibility to measure poroelastic and intrinsic viscoelastic properties of cartilage at similar microscale lengths. Also they encouraged development of broadband cartilage like-dampers and provided important design parameters to maximize their performance.

本文通过研究非耦合的多孔弹性（与流量相关）和固有的粘弹性（与流量无关）能量耗散机制，研究它们对特征长度的依赖性，以了解软骨宽带耗散行为的根源。相移和动态模量是根据在不同接触半径下对水合软骨以及在脱水软骨上进行的动态微压痕测试而测得的。脱水期间记录软骨重量和厚度。相移揭示了在水合软骨中孔隙弹性和粘弹性占主导的耗散状态。具体而言，相对较小半径处的相移受孔隙弹性的支配，而相对较大半径处的相移受固有粘弹性的支配。无耦合的耗散机制表明，固有的粘弹性耗散为所有长度尺度提供了持续的宽带耗散，而额外的多孔弹性耗散增加了小长度尺度下的总耗散。脱水减少了软骨固有的粘弹性消散。这些发现证明了在相似的微尺度长度下测量软骨的多孔弹性和固有粘弹性的可能性。他们还鼓励开发宽带软骨类阻尼器，并提供重要的设计参数以最大化其性能。这些发现证明了在相似的微尺度长度下测量软骨的多孔弹性和固有粘弹性的可能性。他们还鼓励开发宽带软骨类阻尼器，并提供重要的设计参数以最大化其性能。这些发现证明了在相似的微尺度长度下测量软骨的多孔弹性和固有粘弹性的可能性。他们还鼓励开发宽带软骨类阻尼器，并提供重要的设计参数以最大化其性能。