Of the six typical failure modes of a bolted joint, only one is the bolt being pulled apart. This article starts from how a bolted joint works and gives a checklist: which joints need the systematic VDI 2230 calculation, which can do with simplified preselection, and what the standard covers and does not cover.
Irradiation raises yield strength and lowers fracture toughness, so the assessment point of a cracked plate drifts toward the failure assessment line year by year. This post assesses the FITNET training example 'Plate under neutronic irradiation' with the BS 7910 Clause 7 fracture assessment calculator: 12 assessment points are compared one by one with the source, and the most critical point (year 20, 350 MPa) has a reserve factor on load of 1.19 against about 1.2 read from the source chart. All inputs, calculation steps and comparison tables are included.
How a material's yielding behaviour changes the failure assessment line (FAL) in a BS 7910 fracture assessment. What yielding is, how continuous and discontinuous yielding (the Lüders plateau) differ, which materials fall into each group, how to make a safe assumption when you are not sure, and how Option 1 (swap the equations) and Option 2 (one equation, with a Lüders-strain step added to the reference strain) each handle the two cases. With original stress-strain and failure-assessment-line figures, the code equations, and a live online calculator.
A walkthrough of the three assessment options of the BS 7910:2019 Clause 7 Failure Assessment Diagram (FAD): Option 1 (yield/tensile strength only), Option 2 (true stress-true strain curve), and Option 3 (elastic-plastic J-integral). The code equations and their physical reading, how the three failure assessment lines step up in data need, accuracy and conservatism, when to choose which, and the low-strain-hardening exception — with an original comparison figure and a live online calculator.
A guide to BS 7910:2019 Annex P: it explains the physical meaning of the reference stress σ_ref and the reference-stress method, the equivalence of σ_ref and the limit load P_L, how it gives the FAD horizontal axis L_r, the general framework and net-section degradation, the plastic cut-off L_r,max and flow stress, and the calculation steps — with original diagrams and a live worked example.
A guide to BS 7910:2019 Annex M: starting from crack-tip stress singularity, it explains the physical meaning of the stress intensity factor K_I, the general Annex M framework and its correction factors, the semi-elliptical surface-crack solution and evaluation points, the weld-toe magnification factor Mk, and the full calculation steps — with original diagrams and a live worked example.