共查询到20条相似文献，搜索用时 921 毫秒
1.
| 1. | Singular elements with a notch of an arbitrary angle were constructed to determine the stress fields near through notches. |
| 2. | To increase the accuracy of the solution, we constructed transitional singular elements which increase the size of the region re in which singularity is modeled and decrease the incompatibility between the regular and notched singular elements. |
| 3. | A procedure was developed for determining the stress field near notches under dynamic loadings. |
| 4. | The stress intensity factor near small-angle notches differs negligibly from the stress intensity factor near cracks of the same length under static and dynamic loadings. |
| 5. | The finite elements that were constructed make it possible to reliably solve linear fracture mechanics problems by the finite elements method with the use of very coarse idealizations. |
2.
S. B. Kasatkin 《Strength of Materials》1976,8(11):1346-1350
| 1. | Polycarbonate specimens enable direct observation of the stress-strain pattern during the loading process. |
| 2. | It has been shown that under plane strain and plane stress conditions the crack starts at the boundary of the elastic-plastic deformation zone at the moment when the normal stress component reaches the critical value. |
| 3. | Under plane strain conditions the value cr is determined by the yield point and the radius of the notch n. Under plane stress conditions the strip of plastic deformation functions, as a stress concentrator. Fracture occurs when the normal stress component at the boundary reaches the critical value. |
| 4. | During the intervals when the specimen is not loaded the plastically deformed zones act as concentrators of residual stress. When load is again applied there is interaction between the residual stresses and the externally induced stresses. |
3.
L. V. Kuksa B. I. Koval'chuk A. A. Lebedev V. I. Él'manovich 《Strength of Materials》1976,8(6):678-682
| 1. | The use of the method developed for determining the main deformations of microvolumes makes it possible to investigate peculiarities of metal deformation in microareas and the actual level of micrononuniform deformation, taking into consideration the form of stressed condition |
| 2. | A definite character of distribution of the main deformations across microareas, reflecting not only the influence of the form of stressed condition of the macrovolume of a sample, but also the peculiarities of interaction of individual microvolumes which are found in stress deformed conditions differing from the stress deformed condition of the individual body, corresponds to each form of stressed condition. For complex loading a change in the form of distributions of deformations in changing from one form of loading to another is characteristic. |
| 3. | In the plane stressed condition under conditions of simple and complex loading there is intense slip formation accompanied by activation of a larger number of slip systems than in uniaxial loading, which is an indication of the more complex deformation conditions of individual microvolumes. |
| 4. | Differences in the distribution of main deformations across microareas, nonuniformity of the stress deformed conditions of microvolumes, and peculiarities of the character of slip formation undoubtedly play a major role in the formation of mechanical properties in the given forms of stressed condition and methods of complex loading. |
4.
| 1. | As a result of introduction of the system, the possibility of loss of information on the vibration condition of an engine has been eliminated, especiallyin short time appearance of vibrations in failure situations when the vibrations increase very rapidly. |
| 2. | The measuring accuracy has been increased. |
| 3. | Recording of the parameters of vibrations in combination with other parameters characterizing the operation of the engine is provided. |
| 4. | The process of interpreting and treating the test results has been accelerated. |
5.
Joshua D. Shackman 《Management International Review》2007,47(4):479-504
Abstract and Key Results
相似文献
| ▪ | In this paper I test the theory that internal capital markets are a motivation for both corporate diversification and vertical integration. I use a sample of 1560 firms from 39 countries. |
| ▪ | Using this data I also test theories about vertical integration and capital market development. I also test agency cost and taxation theories of diversification and vertical integration. |
| ▪ | I find a significant and negative relationship between corporate diversification and capital market development |
| ▪ | I find a significant and positive relationship between vertical integration and capital market development. |
6.
This article presents a failure analysis of 37.5 mW gas turbine third stage buckets made of Udimet 500 superalloy. The buckets
experienced repetitive integral tip shroud fractures assisted by a low temperature (type II) hot corrosion. A detailed analysis
was carried out on elements thought to have influenced the failure process:
The most probable cause of the bucket damage was the combination of increased stresses due to corrosion-induced thinning of
the tip shroud and unfavorable microstructures in the tip shroud region. 相似文献
| a) | the stress increase from the loss of a load bearing cross-sectional area of the bucket tip shroud by the conversion of metal to the corrosion product (scale), |
| b) | influence of the tip shroud microstructure (e.g., a presence of equiaxed and columnar grains, their distribution and orientation), |
| c) | evidence of the transgranular initiation, and |
| d) | intergranular creep mechanism propagation. |
7.
A new perspective on the regional and global strategies of multinational services firms 总被引：1，自引：0，他引：1
Abstract and Key Results
相似文献
| • | We explore the differences in international strategy between multinational enterprises (MNEs) in services and manufacturing, especially in terms of their international diversification, as measured by their sales and asset dispersion. |
| • | Our longitudinal data show that the largest MNEs in services have a much stronger home-region orientation than manufacturing MNEs. Large MNEs in the services sector average 83.9 percent of their sales in their home region, which is significantly higher than large manufacturing firms at 65.6 percent. |
| • | We explore the possible reasons for the relative lack of globalization of services firms. The two main reasons are: the difficulty of adapting separately upstream activities and downstream activities in high distance host environments, and the difficulty of selecting activity locations as a function of supply side criteria. |
| • | We offer a refinement of regional strategy theory applicable to services MNEs. |
8.
L. V. Kuksa B. I. Koval'chuk A. A. Lebedev V. I. Él'manovich 《Strength of Materials》1976,8(4):393-398
| 1. | Plastic deformation in polycrystalline copper develops unevenly in the microregions in both the linear and the plane stress state (including plane stress under conditions of complex loading). A higher level of microinhomogeneity in deformation was observed in the plane stress state. |
| 2. | The immobilization and duplication of microcenters of increased and reduced deformation in simple loading is a general property of polycrystalline materials and is in independent of the nature of the material and the type of stress state. |
| 3. | The development of deformations in individual microsectors in conditions of complex loading (axial tension—uniform biaxial tension—transverse tension) differs substantially from that in simple loading. The difference lies in the varying degrees of localization of deformation of fixed microsectors. |
| 4. | In a plane stress state, especially under conditions of complex loading, deformation is due to the action of a larger number of slip systems than in a linear stress state; this must indicate more complex deformation conditions in the individual microvolumes. |
9.
T. B. Buzovkina A. N. Sofronkov L. I. Korolenko S. A. Lyaskovskii I. A. Kuznetsova 《Materials Science》1993,28(4):354-358
| 1. | Unstable peroxides are formed when sea water reacts with a nonpassivating steel surface, which results in passivation. |
| 2. | The pH shifts as far as 13 in sea water in a real static crack in 15KhN5 steel, which is accentuated as the stress level increases, the crack lengthens, and the tip is approached. |
| 3. | The alkalinization in sea water above steel turnings is much less than in a crack but the pH dynamics are the same. |
| 4. | Metabolites from aerobic fouling organisms (bicarbonates and oxygen) retard the decomposition of hydrogen peroxide at the surface, which raises the pH and Eh; the metabolites from aerobic bacteria (hydrosulfides) reduce the hydrogen peroxide concentration, which reduces the pH and Eh. |
| 5. | The hydrogen release overvoltage is reduced on peroxide films on steel surfaces of 15KhN5 type, and the cathodic reaction of depolarizer reduction is retarded. |
10.
| 1. | The optimum design theory was used to derive equations for optimizing the stress-strain state in the thick-walled pipe with the elasticity modulus varying along the radius and loaded with the internal pressure. |
| 2. | A numerical method of determining the law of the optimum distribution of the elasticity modulus along the radius of the thick-walled pipe was proposed. |
| 3. | The results show that by corresponding changes of the elasticity modulus in the given range along the pipe thickness it is possible to reduce the maximum annular stresses on the internal surface of the pipe. This stress reduction in a ratio expressed in per cent is approximately equal to the variation range of the elasticity modulus. |
| 4. | The minimum annular strains were recorded in the homogeneous pipe produced from the material with the maximum possible elasticity modulus. |
11.
B. A. Kolachev 《Materials Science》1992,28(5):395-398
| 1. | A general method of improving the composition of the HSA by complex alloying has been proposed. |
| 2. | Systems of alloying the HSA on the basis of intermetallic compounds TiFe, TiCo, TiCr2, TiMn2 have been described and characterized. |
| 3. | It is shown that not all possibilities of complex alloying have been exhausted to improve the properties of the HSA based on titanium. |
12.
| 1. | An algorithm was developed which employs a finite-elements method to solve problems characterized by large dimensions. The algorithm makes it possible to determine the stress-strain state of GTE rotors and to evaluate their load-carrying capacity. |
| 2. | The proposed method of formulating boundary conditions from the results of calculations performed for the assembled rotor makes it possible to determine the stress-strain state of the individual elements with allowance for their interaction. |
| 3. | The results of calculations for the assembled rotor can be used to reliably determine the clearances in the seals. |
| 4. | To reduce the bending strains in cantilevered disks, it is recommended not only that sloping disks be used, but also that the body of the disks be offset relative to the rim. |
13.
Laszlo Tihanyi Robert E. Hoskisson Richard A. Johnson William P. Wan 《Management International Review》2009,49(4):409-431
| • | This paper shows that the role of managerial incentives is highlighted by a relatively complex relationship between technological competence and international diversification. By studying a sample of Standard & Poor’s 500 member firms, we explore the relationships between technological competence, managerial pay, and international diversification. |
| • | Results indicated a curvilinear relationship (an inverted U-shape) between technological competence and international diversification. |
| • | In line with agency theory, contingent pay (stock options and bonuses) was positively related to international diversification. |
| • | Beyond these direct effects, both contingent and non-contingent pay (cash compensation) moderated the relationship between technological competence and international diversification. |
14.
Christos Pitelis 《Management International Review》2007,47(2):207-219
| – | We apply insights from Edith Penrose’s work to extant theory of the multinational enterprise (MNE) as enveloped by John Dunning’s Ownership, Location, Internalization (OLI) Paradigm. |
| – | We suggest that Penrose’s knowledge/learning-based approach has important implications on the nature of, and the interactions between, O, L and I, and it helps endogenize and integrate the three elements of Dunning’s triad in the context of a dynamic, and strategic perspective of the MNE. |
| – | More importantly, a learning-based perspective adds a cognitive dimension to the MNE and OLI. |
| – | This supports a forward looking, synchronic decision making view, that may lead to apparently sub-optimal decisions, taken in view of anticipated changes, along-side strategic behaviour, aiming to effect such change, once decisions have been reached. |
| – | A Penrosean-inspired knowledge/learning-based perspective helps render the OLI more dynamic, strategic and forward looking. |
15.
| 1. | We derived an equation which can be used to determine the endurance in cyclic loading on the basis of the crack initiation criterion in elastoplastic deformation of the material and the triaxial stress state. | ||||||||||||||||||||||||||||
| 2. | Rapid fatigue damage cumulation can take place in the material only if the size of the reversible elastoplastic zone is larger than the grain diameter. | ||||||||||||||||||||||||||||
| 3. | The assumption on the homogeneity of SSS in the structural element makes it possible to describe most adequately the relationship between the strain and fatigue damage of the material. | ||||||||||||||||||||||||||||
| 4. | We derived an analytical expression linking the threshold value of the stress intensity factor \GDKth with the mechanical properties and grain diameter of the material. | ||||||||||||||||||||||||||||
| 5. |
A model of fatigue crack propagation which is based on the approximate analytical solution of the cyclic elastoplastic problem of the SSS in the vicinity of the crack tip was developed. The model takes into account the special features of deformation of the material in the conditions of the triaxial stress state and also uses the assumption on the homogeneity of SSS in the structural element. The main advantages of the model are as follows:
it can be used to determine the crack growth rate in cases in which the variation of the range of the stress intensity factor in the structural members takes place at the variable loading asymmetry; 相似文献
16.
Abstract and Key Results
17.
A note on Penrosean growth,resource bundles and the Uppsala model of internationalisation 总被引：2，自引：1，他引：1
18.
Jean-François Hennart 《Management International Review》2007,47(3):423-452
Abstract and Key Results
19.
20.
|