Assessment of the Structural Integrity of the Portal Crane Elements After Long-Term Operation.

Evaluating the current technical condition and residual life of structures that may have reached or exceeded the end of their design life is a challenging issue in many industrial sectors. This paper focuses on the assessment of the structural integrity of structural elements of a seaport portal crane after operation for about 33 years. Test specimens were extracted from two crane elements, a jib (element A) as the most seriously loaded unit and, for comparison, a boom (element B) as the less loaded one, and machined in two different orientations, longitudinal and transversal.

Specimen Size Effect on the Tensile Properties of Rolled Steel of Long-Term-Operated Portal Crane.

This paper presents the research results on the mechanical behavior of the low-carbon rolled steel of a sea portal crane after a 33-year operation depending on the operational stresses and rolling direction in order to assess its serviceability. The tensile properties of steels were investigated using rectangular cross-section specimens with different thicknesses and the same width. Strength indicators were slightly dependent on the considered factors (operational conditions, the cutting direction, and thickness of specimens).

Some Microstructural Aspects of Ductile Fracture of Metals.

The paper discusses the basic issues of the local approach to ductile fracture of structural metals, with particular emphasis on the failure due to microvoid development. The mechanisms of nucleation of voids around inclusions and precipitates are characterized. The criteria for the nucleation of voids resulting from cracking of the existing particles or their separation from the material matrix are presented.

Assessment of Operational Degradation of Pipeline Steels.

This paper summarizes a series of the authors' research in the field of assessing the operational degradation of oil and gas transit pipeline steels. Both mechanical and electrochemical properties of steels are deteriorated after operation, as is their resistance to environmentally-assisted cracking. The characteristics of resistance to brittle fracture and stress corrosion cracking decrease most intensively, which is associated with a development of in-bulk dissipated microdamages of the material.

On Characteristics of Ferritic Steel Determined during the Uniaxial Tensile Test.

Tensile uniaxial test is typically used to determine the strength and plasticity of a material. Nominal (engineering) stress-strain relationship is suitable for determining properties when elastic strain dominates (e.g.

Investigation of the Fracture Process of Explosively Welded AA2519-AA1050-Ti6Al4V Layered Material.

The study presents an analysis of the cracking process of explosive welded layered material AA2519-AA1050-Ti6Al4V (Al-Ti laminate) at ambient (293 K) and reduced (223 and 77 K) temperatures. Fracture toughness tests were conducted for specimens made of base materials and Al-Ti laminate. As a result of loading, delamination cracking occurred in the bonding layer of specimens made from Al-Ti laminate.

The Use of the Acoustic Emission Method to Identify Crack Growth in 40CrMo Steel.

The article presents the application of the acoustic emission (AE) technique for detecting crack initiation and examining the crack growth process in steel used in engineering structures. The tests were carried out on 40CrMo steel specimens with a single edge notch in bending (SENB). In the tests crack opening displacement, force parameter, and potential drop signal were measured.