Generalized Plane Strain Study of Rotational Autofrettage of Thick-Walled Cylinders—Part I: Theoretical Analysis

Kamal, Seikh Mustafa; Perl, M.; Bharali, Debasish

doi:10.1115/1.4043591

Cited by 7 publications

(4 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Although the idea of rotational autofrettage was theorized only recently in 2016, some researchers had already carried out the elastic-plastic analysis of a rotating hollow cylinder. The analyses can be classified according to three different approaches— plane stress for thin discs, 8–11 generalized plane strain for long cylinders with free ends 12–14 and plane strain for long cylinder with constrained ends. 7 , 15 Rees 8 developed an analytical model for the elastic-plastic analysis of a rotating disc using two approaches.…”

Section: Introductionmentioning

confidence: 99%

“…However, he did not suggest the application of his analysis to autofrettage process. In a two part study, Kamal et al 13 and Kamal and Perl 14 analyzed rotational autofrettage of a free-ended long cylinder, considering a generalized plane strain condition. The material behavior was modeled using the Tresca yield criterion for a perfectly plastic material.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Effect of length in rotational autofrettage of long cylinders with free ends

Shufen¹,

Dixit

2021

Proceedings of the Institution of Mechanical Engineers, Part C:

View full text Add to dashboard Cite

Thick-walled cylindrical and spherical pressure vessels are often subjected to autofrettage, a process in which the vessel is loaded at the inner wall to cause a partial or complete plastic deformation emanating from the inner wall, followed by unloading. This introduces the beneficial compressive residual stresses in the vicinity of the inner wall. Depending on the type of the loading, there are five different types of autofrettage processes— hydraulic, swage, explosive, thermal and rotational. This article analyzes the rotational autofrettage, in which the cylinder to be autofrettaged is loaded by rotating it about its longitudinal axis. The centrifugal forces cause the required plastic deformation in the cylinder. Hence, when the cylinder is unloaded by bringing it to rest, compressive hoop residual stresses are introduced in the vicinity of its inner wall. When long cylinders are rotated about their axes, the distribution of axial stress changes with length of the cylinder and affects the generation of the residual stresses in the autofrettaged cylinder. This effect is investigated here by a finite element method (FEM) analysis of rotational autofrettage of cylinder made up of A723 gun steel. The FEM analysis using ABAQUS® package reveals the presence of tensile axial residual stresses in the vicinity of the inner wall of the cylinder, which increase with length. The tensile residual stresses can be mitigated by constraining the ends of the cylinder during the rotational autofrettage.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Effect of length in rotational autofrettage of long cylinders with free ends

Shufen¹,

Dixit

2021

Proceedings of the Institution of Mechanical Engineers, Part C:

View full text Add to dashboard Cite

show abstract

“…The process was analyzed by a few researchers for strengthening thick cylindrical vessels considering true plane strain 7 , 8 and generalized plane strain conditions. 9 , 10 The problem of rotational autofrettage for strengthening thick-walled hollow circular disk was first addressed by Kamal. 5 For accomplishing rotational autofrettage in disk, the disk is rotated at a sufficiently high angular velocity about its own axis.…”

Section: Introductionmentioning

confidence: 99%

Design of a disk-mandrel assembly for achieving rotational autofrettage in the disk

Kamal

Dixit

2020

Proceedings of the Institution of Mechanical Engineers, Part C:

View full text Add to dashboard Cite

Rotational autofrettage is a recently proposed method to induce beneficial residual stresses in axisymmetric hollow cylindrical bodies. The feasibility of the process has been studied for both disks and cylinders used in many engineering applications. The earlier analyses of rotational autofrettage of disks are based on certain assumptions. One of the crucial assumptions is the free rotation of the disk. However, the free rotation of the disk is practically difficult. In practice, it is feasible to rotate the disk by shrink-fitting it over a solid cylindrical mandrel. In view of this, a design of a disk-mandrel assembly for achieving rotational autofrettage in disks is proposed in this article. The main aim of the design is to obtain appropriate values of the disk-mandrel interference and the rotational speed of the assembly to prevent the loss of contact of the disk with the mandrel during rotation. The critical speeds corresponding to the yield onset, contact separation and the full plastic deformation of the disk are obtained as a function of shrink interference. The safe operating design parameters can be decided by plotting the critical speeds with varying interference values. A detailed stress analysis during elastic-plastic loading of the assembly followed by the analysis of residual stresses in the assembly after unloading is presented. The analysis is based on the plane stress assumption, Tresca yield criterion and elastic unloading. The analysis is validated with a finite element method model in ABAQUS. The proposed design is illustrated through the numerical example of an ASTM A723 disk-mandrel assembly to achieve rotational autofrettage in the disk. With a small overstrain level of 17.5% in the disk, a large magnitude of compressive residual stress, viz., 0.52 times the yield stress, is induced.

show abstract

“…В последнее время приобрела актуальность задача нахождения остаточных напряжений в трубе после вращения. Решение данной задачи используется для описания процесса автофретирования труб за счет вращения [39][40][41][42][43].…”

Section: Introductionunclassified

Elastoplastic deformation of a rotating hollow cylinder with a rigid casing

Prokudin

Firsov

2019

PNRPU Mechanics Bulletin

View full text Add to dashboard Cite

A rotating hollow cylinder with fixed ends is considered, the inner surface of which is free of stresses, and the outer one is fixed from radial movements. It is assumed that the cylinder is made of an ideal isotropic elastoplastic material, and the deformations in it are small and represent the sum of elastic and plastic deformations. Stresses are associated with elastic deformations by Hooke's law. Plastic deformations are determined using the Tresca - Saint-Venant condition and the plastic flow rule associated with it. The cylinder rotation speed first monotonically increases to a maximum value, and then decreases to zero. By using the elastic solution, the dependence is found for the critical rotation speed at which the plastic flow begins. It is established that, depending on the thickness of the cylinder and the Poisson's ratio, plastic flow can begin, either on the inner or on the outer surface of the cylinder. In addition, 3 plastic regions appear in the cylinder at the loading stage, and 4 plastic regions appear at the unloading stage. These regions correspond to two faces and two edges of the Treska prism. For each plastic region, an exact analytical solution of the determining system of equations is found. The system of conditions at the boundaries between the regions providing continuity of the obtained solutions throughout the cylinder is given. Two cases are considered, i.e. the case with a plastic flow which starts first on the inner, and then on the outer surface of the cylinder. Analytical expressions are obtained for rotational speeds at which new regions appear. The relationship between the nucleation rates of the secondary and primary plastic flow is established. The value of the maximum rotation speed sufficient for a complete transition of the cylinder to the state of the secondary plastic flow was also found. It has been revealed that the adding of a rigid casing can significantly increase the resource of an exploited part.

show abstract

Generalized Plane Strain Study of Rotational Autofrettage of Thick-Walled Cylinders—Part I: Theoretical Analysis

Cited by 7 publications

References 22 publications

Effect of length in rotational autofrettage of long cylinders with free ends

Effect of length in rotational autofrettage of long cylinders with free ends

Design of a disk-mandrel assembly for achieving rotational autofrettage in the disk

Elastoplastic deformation of a rotating hollow cylinder with a rigid casing

Contact Info

Product

Resources

About