Relation between impact and fracture toughness of A-387 Gr. B welded joint

The influence of temperature on impact and fracture toughness values in different regions of a welded joint is analysed for low-alloyed Cr-Mo steel A-387 Gr. B, designed for high temperature applications. Standard Charpy specimens were tested on instrumented pendulum to separate total impact energy into energy for initiation and propagation energy for base metal (BM), weld metal (WM) and heat-affected-zone (HAZ). Standard three point bending (3BP) specimens with crack tip located at different regions of a joint (BM, WM, HAZ), were used for fracture toughness testing. Experiments were performed both at the room temperature and at design working temperature, 540 degrees C, which is the focus of this paper, to evaluate temperature effect on both notch and crack resistance for all different regions in a welded joint. Moreover, the relation between crack initiation energy and fracture toughness is established, purely on empirical base

Stress Analysis of Steel Structure Comprising Cylindrical Shell with Billboard Tower

In accordance with EN1993-1-1, in the definition of element classes, the tubular cross section elements are considered as class 3 for cross section that respects the relation: d/t lt = 90 epsilon(2). If for any cross section this relation is not satisfied, the norm is not valid and the cross section is classified as a curved thin walled element - shell element. Thus the design is done according to EN 1993-1-6 normative. The paper presents some aspects regarding the shell design for a case study - a 30 m tall billboard pillar. The designing process is detailed in regard to the used analysis and the ultimate limit states checking. Considering the high stress concentration in the area of the segment joints, design of welded joints is also presented. The Finite Element Method (FEM) is applied as well, showing results in agreement with analytical ones

Influence of temperature on fracture toughness values in different regions of A-387 Gr. B welded joint

The influence of temperature on fracture toughness values in different regions of a welded joint is analysed low-alloyed Cr-Mo steel A-387 Gr. B, designed for high temperature applications. Heterogeneity of microstructure and properties of welded joint is evaluated by testing standard 3BP specimens with crack tip located at different regions of a joint, including the base metal (BM), weld metal (WM) and heat-affected-zone (HAZ). Experiments were performed both at the room temperature and at design working temperature, 5400C. Based on these results, temperature effect on crack resistance is established for all different regions in a welded joint. 2019 The Authors. Published by Elsevier B.V

Influence of temperature on fracture toughness values in different regions of A-387 Gr. B welded joint

The influence of temperature on fracture toughness values in different regions of a welded joint is analysed low-alloyed Cr-Mo steel A-387 Gr. B, designed for high temperature applications. Heterogeneity of microstructure and properties of welded joint is evaluated by testing standard 3BP specimens with crack tip located at different regions of a joint, including the base metal (BM), weld metal (WM) and heat-affected-zone (HAZ). Experiments were performed both at the room temperature and at design working temperature, 5400C. Based on these results, temperature effect on crack resistance is established for all different regions in a welded joint. 2019 The Authors. Published by Elsevier B.V

Influence of temperature and exploitation time on hardness and micro-structure of a welded joint in a reactor mantle

This paper presents the analysis of the influence of temperature and exploitation time on the cross-sectional hardness and microstructure changes of characteristic zones of a welded joint made of low-alloyed Cr-Mo steel A-387 Gr. B. Exploited parent metal is a part of a reactor mantle which was working for over 40 years and is in the damage repair stage, i.e. part of its mantle is being replaced with new material. Cross-sectional hardness of a butt-welded joint was measured and macroscopic investigation of the welded joint and microstructural analysis of the parent material, weld metal and the heat affected zone were performed. The comparison of parameters obtained for characteristic zones of a welded joint provides a way to meausre the justifiability of the selected welding technology

Relation between impact and fracture toughness of A-387 Gr. B welded joint

The influence of temperature on impact and fracture toughness values in different regions of a welded joint is analysed for low-alloyed Cr-Mo steel A-387 Gr. B, designed for high temperature applications. Standard Charpy specimens were tested on instrumented pendulum to separate total impact energy into energy for initiation and propagation energy for base metal (BM), weld metal (WM) and heat-affected-zone (HAZ). Standard three point bending (3BP) specimens with crack tip located at different regions of a joint (BM, WM, HAZ), were used for fracture toughness testing. Experiments were performed both at the room temperature and at design working temperature, 540 degrees C, which is the focus of this paper, to evaluate temperature effect on both notch and crack resistance for all different regions in a welded joint. Moreover, the relation between crack initiation energy and fracture toughness is established, purely on empirical base

Stress Analysis of Steel Structure Comprising Cylindrical Shell with Billboard Tower

In accordance with EN1993-1-1, in the definition of element classes, the tubular cross section elements are considered as class 3 for cross section that respects the relation: d/t ≤ 90ε2. If for any cross section this relation is not satisfied, the norm is not valid and the cross section is classified as a curved thin walled element – shell element. Thus the design is done according to EN 1993-1-6 normative. The paper presents some aspects regarding the shell design for a case study – a 30 m tall billboard pillar. The designing process is detailed in regard to the used analysis and the ultimate limit states checking. Considering the high stress concentration in the area of the segment joints, design of welded joints is also presented. The Finite Element Method (FEM) is applied as well, showing results in agreement with analytical ones

Numerical simulation of tensile testing of pe 80 polymer specimens

The aim of this paper is to present the behaviour of specimens made of polyethylene material PE 80, subjected to tensile load until failure. Measurements of the temperature distribution have been done using the infrared thermography during specimens loading. Finite element analysis was performed in ABAQUS software, where numerical models were made based on the thermograms and force-displacement diagrams obtained from these experiments. Afterwards, results from the simulation were compared with the experimental results and it was determined in which way the model can be optimized so that these results comply at an acceptable level. Numerical model has shown that the highest values of plastic strain were located near the notch. Value of this plastic strain is several times greater than the values in the remaining parts of the specimen. The numerical analysis also determined that defining the load in displacement form was a much better solution than defining it using the force, since the results have shown much better compliance, and the calculation time was much shorter in this case

Effect of temperature and exploitation time on tensile properties and plain strain fracture toughness, K-Ic, in a welded joint

Effect of temperature and exploitation time on resistance to brittle fracture of welded joint constituents of new and 40 years exploited low-alloyed Cr-Mo steel A-387 Gr. B has been analysed. The plane strain fracture toughness is used as the measure of resistance to brittle fracture of base metal, weld metal and heat affected zone from both new and exploited. The stress-strain curves have been determined as well, to get better inside in welded joint behavior. Comparison of the results indicate detrimental effect of both temperature and exploitation time, both for tensile properties and for the resistance to brittle fracture

Composite material selection for aircraft structures based on experimental and numerical evaluation of mechanical properties

In this paper determination of mechanical properties of composite material using experimental and numerical approach is presented. The mechanical properties of a laminate obtained in the experiment are used for verification of numerically obtained values, as well as estimation of the load-carrying capacities of composite engine cover of light aircraft. Composite specimens, consisting of epoxy matrix and glass fibers with orientation angles 0 degrees, 45 degrees, and 90 degrees, have been made according to standards, and the mechanical properties were investigated in tensile and three-point bending tests. The tensile strength, bending strength, elasticity modulus, strain, and force at laminate failure have been evaluated and then compared to values obtained in numerical simulations with the aim of verifying the FE model used for failure prediction of structural laminates. Good agreement of experimental and numerical values provides a solid foundation for further improvements of the numerical model