Time-dependent reliability index for continuum structures against field uncertainty based on non-probabilistic bounded field model

Abstract

The advancement of soft robotics technology has spurred a growing interest in understanding the time-dependent reliability of continuum structures. This study introduces a novel non-probabilistic model for assessing the time-dependent reliability index of continuum structures under the influence of non-probabilistic bounded field uncertainties. Utilizing the non-probabilistic series expansion (NPSE), the field uncertainties are quantified through a collection of NPSE coefficients, offering a comprehensive representation of the uncertainty in the system. By considering the time variable as an uncertain parameter, the time-dependent reliability analysis can be reformulated as a time-independent problem, allowing for the development of a non-probabilistic reliability index that accounts for both time parameter and field uncertainties. A time-dependent reliability index is introduced utilizing the concerned performance method to assess the structural reliability throughout varying time intervals. Subsequently, the efficacy and applicability of the proposed non-probabilistic time-dependent reliability model were illustrated through three numerical example studies involving geometrically linear and nonlinear time-dependent structures. The findings highlight the effectiveness and practicality of the proposed approach in facilitating the evaluation of the reliability of time-dependent issues while accounting for field uncertainties.