Abstract
Experimentally investigated patterns of changes in technological residual stresses under the influence of variable pressure in the surface layer became 30XNS2A. A mathematical model of relaxation of residual compressive stresses created by surface plastic deformation techniques with symmetrical cyclical bending of samples has been proposed. An empirical expression is proposed for assessing the final value of residual stresses as a result of cyclic loading, depending on the stress amplitude of a symmetric cycle. An expression is given for estimating the coefficient of relaxation rate of residual compressive stresses from their initial value, amplitude of alternating stresses and material properties. The constants of these expressions are determined for various construction materials. The theoretical dependences describe well the obtained experimental data. To predict the level of residual stress realization under operational loading, a formula was obtained to calculate their change as a result of the action of a step loading block with different amplitudes and duration of their action at each of the stages.
Highlights
IntroductionMany aircraft parts, such as runway elements, power cylinders of hydro systems, unit nodes and wing mechanization units and many others, are made of high-strength steel, titanium and aluminum alloys, including the widely used steel 30XNS2A
Many aircraft parts, such as runway elements, power cylinders of hydro systems, unit nodes and wing mechanization units and many others, are made of high-strength steel, titanium and aluminum alloys, including the widely used steel 30XNS2A. All of these units and nodes in operation are exposed to the force of variable loads, and their resource is determined by the characteristics of resistance to fatigue and durability
The tendency to increase the resource of transport and passenger aircraft to 60-70 thousand. the flight clock makes the problem of studying the relaxation patterns of favorable fields of residual compressive stresses even more relevant
Summary
Many aircraft parts, such as runway elements, power cylinders of hydro systems, unit nodes and wing mechanization units and many others, are made of high-strength steel, titanium and aluminum alloys, including the widely used steel 30XNS2A. All of these units and nodes in operation are exposed to the force of variable loads, and their resource is determined by the characteristics of resistance to fatigue and durability. The main role in increasing the resource of these parts, made of high-strength steels and titanium alloys, is played by residual compressive voltages created in the process of PPD. The tendency to increase the resource of transport and passenger aircraft to 60-70 thousand. the flight clock makes the problem of studying the relaxation patterns of favorable fields of residual compressive stresses even more relevant
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
