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This study aims to find suitable fatigue assessment methods for welded structures (cover plates and T‐joints) subjected to axial and bending loading. The Hot Spot Stress (HSS), 1‐mm stress (OM), Theory of Critical Distances (TCD), Stress Averaging (SA), and Effective Notch Stress (ENS) methods are evaluated in terms of accuracy and reliability. The evaluation is based on fatigue test data extracted from the literature and carried out in this study. It is found that the SA method can be used to assess the fatigue strength of cover plate joints under axial loading with relatively good accuracy and low scatter, followed by the ENS method. The HSS, TCD, SA, and ENS methods are conservative estimation methods for T‐joints under bending, while the accuracy is low. Furthermore, fatigue design curves applicable for T‐joints under bending are discussed, which can be used in the TCD method and SA method. [ABSTRACT FROM AUTHOR]

This study investigates stress‐based fatigue assessment methods to determine their applicability to welded cover plate joints subject to axial and bending loading. The nominal stress (NS), hot spot stress (HSS), 1 mm stress (OM), effective notch stress (ENS), theory of critical distances (TCD), and stress averaging (SA) methods are covered, and their accuracy and reliability are evaluated. To the best of the authors' knowledge, there is limited fatigue test data available for cover plate joints subjected to bending loading. In this study, fatigue tests are performed with cover plate joints under axial and bending loading. Evaluation of the fatigue assessment methods is based on the test results. It is observed that for axial loading, the ENS and OM method have the highest accuracy. For bending, the OM method is non‐conservative, and the other methods are overly conservative. Using design curves recommended for thin‐walled welded joints subjected to bending highly improves accuracy. Highlights: This study evaluates fatigue strength assessment methods in terms of accuracy and reliability.This study provides a better understanding about cover plate joints in bending.New test data are generated for high strength steel cover plate joints in axial and bending load.Fatigue strength classes are recommended based on experiments. [ABSTRACT FROM AUTHOR]

[Display omitted] • A methodology is proposed to design novel isosurface strut lattice structure (ISLS) derived from TPMS. • Structural element of ISLS were modeled using beam and solid tetrahedron elements. • Stiffness, Anisotropy index, and fatigue properties were determined. • Anisotropy analysis showed that ISLS exhibit near isotropic behavior for all relative densities. • Low elastic modulus and superior fatigue resistance demonstrate suitability of ISLS as biomaterial scaffolds. This paper proposes a novel methodology to design a family of strut-based lattice structures derived from isosurfaces. Here the methodology is applied on isosurfaces obtained from Triply Periodic Minimal Surfaces (TPMSs). A Schoen's Gyroid TPMS morphology was employed to generate an isosurface strut lattice structure (ISLS). The structural element of ISLSs were modeled as solid tetrahedral and beam elements. Finite element simulations were performed to compute the effective mechanical properties such as stiffness, anisotropy index and fatigue properties for range of relative densities, i.e., 5% to 35%. An isosurface strut mesh sensitivity study was performed to determine number of mesh points required for consistency in mechanical properties. Stretch dominated sheet Gyroids are found to be most superior lattices for mechanical properties in literature and hence the truss based ISLS is compared to sheet Gyroids. The scaling laws demonstrated that Gyroid ISLS modelled with both beam elements and solid elements exhibited bending dominated behavior and yet ISLS solid elements show an elastic modulus, bulk modulus, and shear modulus, comparable to stretch-dominated sheet Gyroids. Anisotropy analysis showed that ISLS exhibit near isotropic behavior for all relative densities. Results exhibited that for the same relative density, ISLS modelled with beam elements showed lower elastic modulus, but higher fatigue performance as compared to the solid elements. Highly porous, low elastic modulus and superior fatigue resistance demonstrate suitability of ISLS beam as biomaterial scaffolds whereas ISLS solid having high modulus are useful in applications requiring enhanced mechanical strength. [ABSTRACT FROM AUTHOR]