Lifetime predictions of prestressed concrete bridges—Evaluating parameters of relevance using Sobol' indices

Sanio, David; Ahrens, Alexander; Mark, Peter

doi:10.1002/cend.202100009

Cited by 2 publications

(2 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In comparison to qualitative methods, so-called screening methods [45] require significantly fewer evaluations. Typically, they are used to identify decisive or less relevant parameters, for example, to reduce complex models [46]. Subsequently, a quantitative sensitivity analysis can be carried out in a then reduced design space [41].…”

Section: Sensitivity Analysis Of Modular Structuresmentioning

confidence: 99%

“…In contrast, other sensitivity analysis techniques, e.g., sensitivity-based total effects [50], require N•(k + 2) simulations, in which the sample size N varies between a few hundreds to thousands and more depending on the model under investigation [41]. Already with N = 100, which is still much too low for reliable results [46], the EE method requires more than 10 times fewer simulations. This is why the EE method is adapted for the analysis of relevant module positions that mainly cause deformations on an overall structure.…”

Section: Sensitivity-based Permutation Approachmentioning

confidence: 99%

See 1 more Smart Citation

Sensitivity-Based Permutation to Balance Geometric Inaccuracies in Modular Structures

Forman,

Ahrens,

Mark

2024

Sustainability

View full text Add to dashboard Cite

In modular structures, inaccuracies of the modules superimpose over the entire structure. Depending on the placement of the modules, these inaccuracies have (different) effects on stresses and total deformations. Especially for structures with many individual modules, it is favorable to place them according to their influence. To cover structural diversity, column-, beam-, and wall-like modular structures made from plane modules are investigated. In numerical simulation, geometric inaccuracies are applied via an equivalent temperature approach, which allows almost arbitrary nodal deviations of the modules. With the elementary effects method, the sensitivities of the modules’ inaccuracies regarding their structural impact can be determined with minimal computational effort. On a predefined control node, the overall structural inaccuracies are examined in a simplified manner. Column-like structures experience higher deformations due to inclination than beam-like or wall-like structures. For column-like, the bottommost modules are decisive for the overall inaccuracy, as they contribute significantly to the inclination. By contrast, modules at the supports are identified as particularly sensitive for beam- and wall-like structures. Controlling module placement towards their mean absolute influence, the deformation at the control node is mathematically reduced by at least 43% compared to random placement. Thereby, even modules that do not comply with tolerance requirements for structural components can be used in areas of low influence for a sustainable and low-waste design.

show abstract

Section: Sensitivity Analysis Of Modular Structuresmentioning

confidence: 99%

Section: Sensitivity-based Permutation Approachmentioning

confidence: 99%

Sensitivity-Based Permutation to Balance Geometric Inaccuracies in Modular Structures

Forman,

Ahrens,

Mark

2024

Sustainability

View full text Add to dashboard Cite

show abstract

Modification of Variance-Based Sensitivity Indices for Stochastic Evaluation of Monitoring Measures

Sanio¹,

Ahrens²,

Mark³

2021

Infrastructures

View full text Add to dashboard Cite

In complex engineering models, various uncertain parameters affect the computational results. Most of them can only be estimated or assumed quite generally. In such a context, measurements are interesting to determine the most decisive parameters accurately. While measurements can reduce parameters’ variance, structural monitoring might improve general assumptions on distributions and their characteristics. The decision on variables being measured often relies on experts’ practical experience. This paper introduces a method to stochastically estimate the potential benefits of measurements by modified sensitivity indices. They extend the established variance-based sensitivity indices originally suggested by Sobol’. They do not quantify the importance of a variable but the importance of its variance reduction. The numerical computation is presented and exemplified on a reference structure, a 50-year-old pre-stressed concrete bridge in Germany, where the prediction of the fatigue lifetime of the pre-stressing steel is of concern. Sensitivity evaluation yields six important parameters (e.g., shape of the S–N curve, temperature loads, creep, and shrinkage). However, taking into account individual monitoring measures and suited measurements identified by the modified sensitivity indices, creep and shrinkage, temperature loads, and the residual pre-strain of the tendons turn out to be most efficient. They grant the highest gains of accuracy with respect to the lifetime prediction.

show abstract

Lifetime predictions of prestressed concrete bridges—Evaluating parameters of relevance using Sobol' indices

Cited by 2 publications

References 34 publications

Sensitivity-Based Permutation to Balance Geometric Inaccuracies in Modular Structures

Sensitivity-Based Permutation to Balance Geometric Inaccuracies in Modular Structures

Modification of Variance-Based Sensitivity Indices for Stochastic Evaluation of Monitoring Measures

Contact Info

Product

Resources

About