The complexity behind dissipative phenomenon is still a major source of uncertainty in structural dynamics. This phenomenon is usually simplified to a deterministic proportional damping, disregarding the effects of modal coupling in the analysis. In this work, a probabilistic model is developed for non-proportional damping by adding uncertainties globally in the damping operator. The two main hypotheses of the resulting random damping matrix are: (i) it is symmetric positive definite and (ii) it is expected to be diagonal dominant. Several analyses are conducted, comparing proportional and non-proportional models. In addition, experimental data are used in the identification procedure of the random model. The proposed probabilistic model might be employed to other matrices, if the fundamental hypotheses are respected.

耗散现象背后的复杂性仍然是结构动力学不确定性的主要来源。这种现象通常被简化为确定性的比例阻尼，而忽略了分析中模态耦合的影响。在这项工作中，通过在阻尼算子中全局添加不确定性，为非比例阻尼开发了一个概率模型。产生的随机阻尼矩阵的两个主要假设是：（i）它是对称正定的；和（ii）它是对角线主导的。进行了一些分析，比较了比例模型和非比例模型。另外，在随机模型的识别过程中使用了实验数据。如果遵守基本假设，则建议的概率模型可以用于其他矩阵。