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1

Effective fatigue damage summation

100%
Kolenda J.
Polish Maritime Research
|
2006
|
tom 13
|
nr 4
The cumulative fatigue damage caused by uniaxial variable stress is considered. To facilitate the lifetime prediction at complex stress patterns, has been defined an effective stress ofconstant parameters, claimed to be equivalent to the sequence of original stresses in terms of fatigue life of material. The equivalence conditions are based on the theory of energy transformation systems. To the effective stress the Palmgren-Miner rule is applied. Thereby the cycle counting is not required
2

On the behaviour of viscoelastic solids under multiaxial loads

100%
Kolenda J.
Polish Maritime Research
|
2008
|
tom 15
|
nr 3
On the basis of modified Hooke’s law for multiaxial stress in viscoelastic solids, three-dimensional constitutive equations for strains have been derived. It is shown that after application or removal of triaxial static load, normal and shear strain components vary in course of time proportionally to each other and that in-phase stress components produce in-phase strain components. Harmonic out-of-phase stress as well as multiaxial periodic and stationary random stresses are also considered. The matrix of dynamical flexibilityofviscoelastic materials is determined which depends on three material constants (Young modulus, Poisson’s ratio and coefficient of viscous damping of normal strain) and loadcircular frequency
3

High-cycle fatigue criterion for anisotropic metals under multiaxial constant and periodic loads

100%
Kolenda J.
Polish Maritime Research
|
2005
|
tom 12
|
nr 4
Periodic stress with Cartesian components given in the form of Fourier series is considered. To account for the mean stress effect the modified Soderberg’s formula is employed.An equivalent stress with synchronous components is defined. The design criterionfor a finite fatigue life of metal elements is formulated. It covers the conditions of bothstatic strength and fatigue safety in the high-cycle regime and includes material constantswhich have simple physical interpretation, can be determined by uniaxial tests, are related directly to the applied loads, and can reflect material anisotropy
4

On the fatigue-critical amplitude of random-amplitude stress

100%
Kolenda J.
Polish Maritime Research
|
2007
|
tom 14
|
nr 2
Uniaxial non-zero mean stress of constant circular frequency in the high-cycle fatigue regime is considered. It is assumed that equation of the S-N curve and modified Soderberg equation are applicable. For constant-amplitude stress, the fatigue-critical stress amplitude is defined as that which leads to failure during the required design life. For random-amplitude stress, expected values of the fatigue-critical stress amplitude and total fatigue damage accumulated during the required design life are estimated. It is found that the probability of fatigue failure is equal to the probability of exceedance of the fatigue- -critical stress amplitude. As an example, for stationary random stress the equivalent random-amplitude stress and probability of fatigue failure are determined
5

Fatigue "safe-life" criterion for metal elements under multiaxial static and dynamic random loads

100%
Kolenda J.
Polish Maritime Research
|
2004
|
tom 11
|
nr 3
Random stress with Cartesian components of known statistical moments of their meanvalues and power spectral densities of stochastic stress processes is considered. To acco-unt for the mean stress effect the generalised Soderberg criterion for ductile materials isemployed. An equivalent stress with periodic (in the mean-square sense) components isdefined by means of the equivalence conditions based on the average strain distortionenergy. Also, is formulated the fatigue "safe-life" design criterion which covers the condi-tions of both static strength and fatigue safety and includes yield strengths and fatiguelimits which : have simple physical interpretation, can be determined by uniaxial tests, are directly relatedto the applied loads, and can reflect material anisotropy
6

Fatigue "safe-life" criterion for metal elements under multiaxial constant and periodic loads

100%
Kolenda J.
Polish Maritime Research
|
2004
|
tom 11
|
nr 2
Periodic stress with Cartesian components given in the form of Fourier series is conside-red. To account for the mean stress effect the generalised Soderberg criterion for ductilematerials is employed. An equivalent stress with synchronous components is defined bymeans of the equivalence conditions based on the average strain energy of distortion. Thefatigue "safe-life" design criterion is formulated which covers the conditions of both staticstrength and fatigue safety and includes material constants that have simple physical in-terpretation, can be determined by uniaxial tests, are related directly to the applied loadsand can reflect material anisotropy
7

Modification of Hooke's law for multiaxial stress in viscoelastic solids

100%
Kolenda J.
Polish Maritime Research
|
2008
|
tom 15
|
nr 2
On the basis of Hooke’s law for multiaxial stress in elastic solids, similar relationships for viscoelastic materials are considered. It is assumed that the material is homogeneous and isotropic, and that the Kelvin-Voigt’s model is applicable to normal strain components. An analogous model is also taken for shear strain components. It is shown that the ratio of coefficients of viscous damping of normal and shear strain components is equalto the ratio of Young modulus and shear modulus. As a result, the modified Hooke’s law for multiaxial stress in viscoelastic materials has been formulated which includes three material constants: Young modulus, Poisson’s ratio and coefficient of viscous damping of normal strain
8

Dissipation energy in viscoelastic solids under multiaxial loads

100%
Kolenda J.
Polish Maritime Research
|
2008
|
tom 15
|
nr 1
On the basis of the three-dimensional constitutive equations for strains resulting from the Kelvin-Voigt’s model and modified Hooke’s law for multiaxial stress in viscoelastic solids,the formulae for the energy dissipated in a given time per unit volume have been derived. It is shown that after application or removal of triaxial static load there is no difference in the time functions governing the dissipation of strain energy of volume change and the dissipation of strain energy of distortion. Harmonic in-phase stress and harmonic out-of-phase stress as well as multiaxial periodic stress are also considered. It is demonstrated that in the process of energy dissipation due to normal and shear stress components the role of the latter is dominant
9

Failure criteria of viscoelastic materials under multiaxial loads

100%
Kolenda J.
Polish Maritime Research
|
2009
|
tom 16
|
nr 1
The load capacity of homogeneous, isotropic viscoelastic materials subjected to multiaxial stresses is considered. For this purpose uniaxial equivalent stresses in selected load cases are determined and relevant criteria applied. It is shown that in the case of constant load the yield criterion does not differ from that for perfectly elastic materials. Similar conclusion has been drawn for the fatigue and yield criteria at in-phase and out-of-phase stresses. On the contrary, the criteria derived for viscoelastic materials subjected to periodic loads do not coincide with those for perfectly elastic materials
10

A modification of distortion - energy theory at static-dynamic random loading

100%
Kolenda J.
Polish Maritime Research
|
1999
|
tom 06
|
nr 2
11

On the use of theory of energy transformation systems in fatigue calculations of steel elements

100%
Kolenda J.
Polish Maritime Research
|
2001
|
tom 08
|
nr 3
12

Integrated safety factors in design for infinite and finite fatigue lives of steel elements at multiaxial static and periodic loadings

100%
Kolenda J.
Polish Maritime Research
|
2000
|
tom 07
|
nr 1
13

W trosce o srodowisko

88%
Kolenda J.
Sygnały Rolnicze. Ośrodek Doradztwa Rolniczego w Kościelcu
|
1999
|
nr 04
40-41
14

Susze owocowo-warzywne

88%
Kolenda J.
Sygnały Rolnicze. Ośrodek Doradztwa Rolniczego w Kościelcu
|
1999
|
nr 09
36-37
15

Spectral criterion of infinite fatigue life of beams under combined random loads

88%
Kolenda J.
Polish Maritime Research
|
2002
|
tom 09
|
nr 2
16

Zywmy sie zdrowo

88%
Kolenda J.
Sygnały Rolnicze. Ośrodek Doradztwa Rolniczego w Kościelcu
|
2000
|
nr 10
30
17

Mleko zrodlem zdrowia

75%
Kolenda J.
Sygnały Rolnicze. Ośrodek Doradztwa Rolniczego w Kościelcu
|
1998
|
nr 05
37
18

Surowki i salatki w codziennej diecie

75%
Kolenda J.
Sygnały Rolnicze. Ośrodek Doradztwa Rolniczego w Kościelcu
|
1999
|
nr 02
23-24
19

Fatigue criterial parameters of variable amlitude stress

75%
Kolenda J.
Polish Maritime Research
|
2003
|
tom 10
|
nr 4
20

Przetwory w gospodarstwie domowym

75%
Kolenda J.
Sygnały Rolnicze. Ośrodek Doradztwa Rolniczego w Kościelcu
|
1997
|
nr 07
28-29
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