ENGINEERING TRANSACTIONS
ROZPRAWY IN¯YNIERSKIE
A QUARTERLY JOURNAL
- J. Maciejewski, H. Kopeæ, H. Petryk:
Finite element analysis of strain non-uniformity in two processes of severe plastic deformation
- W. Morzuch:
Dynamic buckling of a sandwich bar compressed by periodically variable force
- Z. Zatorski:
Evaluation of steel clad plate weldability using ram tensile test method
- P. Ko³akowski:
Structural health monitoring - a review with the emphasis on low-frequency methods
- J. Maciejewski, H. Kopeæ, H. Petryk:
Finite element analysis of strain non-uniformity in two processes of severe plastic deformation
- Two severe plastic deformation (SPD) processing techniques, namely
equal-channel angular pressing (ECAP) and cyclic extrusion-compression
(CEC), are investigated by using the finite element method. The major
aspect examined is the non-uniformity of the accumulated, equivalent plastic
strain after processing with the use of different shapes of the die. The
quantitative effect of several parameters on the plastic flow is determined.
It is found that the diameter ratio of the chambers and narrower channel
in the CEC method, and also the inclination angle of connecting conical
parts, can affect strongly the degree of strain non-uniformity. Comparison
is made of distributions of equivalent strain after two passes of ECAP for
two different routes and with two die profiles.
Contents
- W. Morzuch:
Dynamic buckling of a sandwich bar compressed by periodically variable force
- The paper presents an analysis of dynamic buckling of a sandwich bar
compressed by a periodically variable force. In order to determine the stability of the bar transverse motion equations of its transverse vibration were formulated. From the equations of motion, differential equations interrelating of the bar dynamic deflection with space and time were derived. The partial differential equations were solved using the method of separation of
variables (Fourier's method). Then an ordinary differential equation (Hill's equation) describing the bar vibration was solved. An analysis of the solution became the basis for determining the regions of sandwich bar motion
instability. Finally, the critical damping coefficient values at which parametric resonance occurs have been calculated.
Contents
- Z. Zatorski:
Evaluation of steel clad plate weldability using ram tensile test method
- The weldability evaluation of steel clad plate is performed using the ram
tensile test method. Numerical analysis of considered problem is performed
using the finite elements method. The author introduces and verifies a critical ram tension strength R0 above the yield strength RIIe - as the criterion of the weldability evaluation of clad steel plate, where: RIIe /RIe < 0.707,
RIIe, RIe - yield strengths of soft and hard materials.
Contents
- P. Ko³akowski:
Structural health monitoring - a review with the emphasis on low-frequency methods
- Structural Health Monitoring (SHM) is a fast-developing, interdisciplinary field of research having its roots in vibroacoustics and non-destructive testing and evaluation. Fast development of the area is due to the fact that
SHM is heavily stimulated by the engineering problems of maintenance and
safe operation of technical infrastructure. The use of SHM is slowly becoming a standard in high-cost, modern infrastructure. Therefore, the possibility of application should always be on the horizon of any related research work.
Thus far, the majority of SHM applications have been demonstrated in civil, aerospace and mechanical engineering. This paper reviews the main achievements and points out the current trends in this field with the emphasis on
low-frequency methods.
Contents
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