scholarly journals Determination of maximum axial loads at the stage of operation of non-rigid pavements based on the analysis of complete deformation diagrams

2019 ◽  
Vol 6 (2) ◽  
Author(s):  
Evgenia Uglova ◽  
Artem Tiraturyan ◽  
Evgeny Roman ◽  
Evgeny Belousov
Keyword(s):  
Axial Load ◽  
Dissipated Energy ◽  
Axial Loads ◽  
Road Design ◽  
Load Limit ◽  
Proportional Increase ◽  
Complete Deformation ◽  
Definition Of ◽  
The Impact ◽  
Deformation Diagrams

The article is devoted to the development and experimental justification of the possibility of determining the axial loads of flexible pavements on the basis of full deformation diagrams recorded under shock loading. Results: The drawbacks of the existing regulatory methods for determining the axial load limit from the impact of vehicles at the operation stage are considered. It is noted that the definition of axial loads only on the strength factor, has several disadvantages associated with the need for information on the design value of the modulus of elasticity of the pavement, as well as the inconsistency of the existing regulatory framework for road design with real traffic loads. It is proposed to determine the maximum axial loads on the basis of the analysis of the complete deformation diagrams recorded at different values of the dynamic load shock load. For the first time, an approach to determining axial loads is proposed, based on the construction of a curve in the coordinates “increase of dissipated energy (ΔW) – load on the coating (F)”, and the load initiating the transition from proportional increase of the dissipated energy with increasing contact load, disproportionately. An example is given of determining the maximum axial load on the pavement cover for the exploited section of the M4 “DON” highway Conclusions: The possibility of determining the limiting axial loads on the pavement coating, based on the analysis of the complete deformation diagrams recorded during impact loading on the pavement coating, was experimentally justified. The need for further improvement and a set of a database of experimental data on changes in limiting axial loads in different periods of the year is noted.

Fatigue Life of Sn3.0Ag0.5Cu Solder Alloy Under Combined Cyclic Shear and Constant Tensile/Compressive Loads

2020 ◽  
Vol 142 (4) ◽  
Author(s):  
Travis Dale ◽  
Yuvraj Singh ◽  
Ian Bernander ◽  
Ganesh Subbarayan ◽  
Carol Handwerker ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Axial Load ◽  
Solder Joints ◽  
Axial Loads ◽  
Cyclic Shear ◽  
Lap Shear ◽  
Shear Loads ◽  
Area Array ◽  
Compressive Loads ◽  
The Impact

Abstract Solder joints in electronic assemblies experience damage due to cyclic thermomechanical loading that eventually leads to fatigue fracture and electrical failure. While solder joints in smaller, die-sized area-array packages largely experience shear fatigue due to thermal expansion mismatch between the component and the substrate, larger area-array packages experience a combination of cyclic shear and axial tensile/compressive loads due to flexure of the substrate. Additionally, on larger processor packages, the attachment of heatsinks further exacerbates the imposed axial loads, as does package warpage. With the increase in size of packages due to 2.5D heterogeneous integration, the above additional axial loads can be significant. Thus, there exists a critical need to understand the impact on fatigue life of solder joints with superposed compressive/tensile loads on the cyclic shear loads. In this paper, we describe a carefully constructed multi-axial microprecision mechanical tester as well as fatigue test results on Sn3.0Ag0.5Cu (SAC305) solder joints subjected to controlled cyclic shear and constant compressive/tensile loads. The tester design allows one to apply cyclic shear loads up to 200 N while maintaining a constant axial load of up to 38 N in tension or compression. The tester is capable of maintaining the axial load to within a tolerance of ±0.5 N during the entirety of fatigue experiment. Carefully constructed test specimens of Sn3.0Ag0.5Cu solder joints were isothermally fatigued under systematically increased compressive and tensile loads imposed on the test specimen subject to repeated loading (R = 0) under lap-shear. In general, the imposition of the superposed compressive load increases the fatigue life of the solder joint compared to application of pure cyclic shear, while the imposition of the superposed tensile load decreases the fatigue life. At larger compressive loads, friction between fractured surfaces is responsible for significant energy dissipation during the cyclic load–unload cycles.

Influence of duration and frequency of load application on the stress-strain state of the track

2018 ◽  
Vol 77 (6) ◽  
pp. 364-367
Author(s):  
M. M. Zheleznov ◽  
V. O. Pevzner ◽  
V. P. Solov’ev ◽  
A. V. Anisin ◽  
I. M. Anisina ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Axial Load ◽  
Strain State ◽  
Load Application ◽  
Axial Loads ◽  
Test Program ◽  
Stress Strain ◽  
The Road ◽  
Different Characteristics ◽  
The Impact

Abstract. In 2014–2016 on the Kovdor—Pinozero section of Oktyabrskaya Railway tests were carried out on the impact of cars with axial loads of 245.3 and 264.9 kN on the track in comparison with standard cars with an axial load of 230.5 kN. Test program included trips to five experimental sections of the track with the same construction of the track superstructure, but different parameters of the road bed. Tests carried out on the impact on the track of trains weighing from 2000 to 8000 tons at different axial loads of cars and moving at different speeds made it possible to estimate the dependence of the growth of vertical forces acting on the rail on the duration and frequency of load application. Work on the registration of vertical forces was carried out by the specialists of the Department “Tracks and track facility” of the JSC “VNIIZhT”. On the basis of the results obtained, a mathematical model was developed that describes the effect of increasing the impact of railcars on the track as the load application increases, allowing calculations for various characteristics of the base. In the future, it is planned to use this model to estimate the accumulation of deformations of the track with different characteristics of the base and variants of train load. Obtained results allow stating that the accumulation of track failures depends not only on the level of the axial load and the mass of the train, but also on the duration and frequency of the load application. 

Methodical approaches to the economic assessment of costs in the operation of cars with axial load of 27 tons at the section Kachkanar—Smychka

2018 ◽  
Vol 77 (6) ◽  
pp. 347-356
Author(s):  
G. A. Granovskaya ◽  
A. I. Safonova ◽  
O. A. Suslov ◽  
N. S. Okhotnikov
Keyword(s):  
Axial Load ◽  
Economic Effect ◽  
Economic Assessment ◽  
Axial Loads ◽  
Railway Line ◽  
Experimental Section ◽  
Calculation Algorithms ◽  
Infrastructure Maintenance ◽  
The Cost ◽  
The Impact

Abstract. The most important direction of increasing the efficiency of rail transportation is to increase the load-carrying capacity of freight cars as a result of an increase in axial loads. New car 12-9548-01 with improved technical characteristics has an axial load of 27 tons. The article describes method of calculating the coefficient reflecting the change in the impact of cars with an axial load of 27 tons on the roadbed during transportation in estimated cars compared to transportation in equivalent cars. Algorithms for calculating changes in the cost of fuel and energy costs for train traction and maintenance of the track infrastructure on the site during the operation of trains formed from cars with an axial load of 27 tons are given, as well as methods for determining the initial data for the calculation.Authors provide values of the coefficient reflecting the change in the impact of vertical and horizontal forces on the railway line when passing freight cars with an axial load of 27 tons compared to analogue cars, and the coefficient of change of the main specific resistance to motion separately for loaded and empty cars.Developed calculation algorithms and methods for obtaining baseline data allow an economic assessment of changes in infrastructure maintenance costs and fuel and energy resources for the operation of trains formed from cars with an axial load of 27 tons compared to those formed from cars with a load of 23.5 tons at the experimental section Kachkanar—Smychka.The cost change assessment carried out in 2017 shows a generally definite economic effect, while there is a reduction in costs associated with the consumption of electricity for train traction as a result of the operation of the estimated cars in the experimental section and an increase in the cost of maintaining the track superstructure and the roadbed, which is quite expected for the conditions of the organization of traffic with increased axial loads.

PERTANGGUNGJAWABAN KERUGIAN NEGARA DALAM PENGELOLAAN KEUANGAN DAERAH

EDUKASI ◽  
2018 ◽  
Vol 16 (1) ◽  
Author(s):  
Hendra Karianga
Keyword(s):  
Financial Management ◽  
Criminal Liability ◽  
The State ◽  
Legal Proceedings ◽  
Regional Finance ◽  
Regional Budget ◽  
State Finance ◽  
Budget Policy ◽  
Definition Of ◽  
The Impact

Sources of revenue and expenditure of APBD (regional budget) can be allocated to finance the compulsory affairs and optional affairs in the form of programs and activities related to the improvement of public services, job creation, poverty alleviation, improvement of environmental quality, and regional economic growth. The implications of these policies is the need for funds to finance the implementation of the functions, that have become regional authority, is also increasing. In practice, regional financial management still poses a complicated issue because the regional head are reluctant to release pro-people regional budget policy, even implication of regional autonomy is likely to give birth to little kings in region causing losses to state finance and most end up in legal proceedings. This paper discusses the loss of state finance and forms of liability for losses to the state finance. The result of the study can be concluded firstly,  there are still many differences in giving meaning and definition of the loss of state finace and no standard definition of state losses, can cause difficulties. The difficulty there is in an effort to determine the amount of the state finance losses. The calculation of state/regions losses that occur today is simply assessing the suitability of the size of the budget and expenditure without considering profits earned by the community and the impact of the use of budget to the community. Secondly, the liability for losses to the state finance is the fulfillment of the consequences for a person to give or to do something in the regional financial management by giving birth to three forms of liability, namely the Criminal liability, Civil liability, and Administrative liability.Keywords: state finance losses, liability, regional finance.

Empowering Women Entrepreneurs Through Microfinance - A Case of Rural Bangladesh

2017 ◽  
Vol 3 (2) ◽  
pp. 7
Author(s):  
Saida Parvin
Keyword(s):  
Women's Empowerment ◽  
Assessment Tools ◽  
Women’S Empowerment ◽  
Case Study Method ◽  
Policy Makers ◽  
Theoretical Contribution ◽  
Donor Agencies ◽  
Definition Of ◽  
The Impact

Women’s empowerment has been at the centre of research focus for many decades. Extant literature examined the process, outcome and various challenges. Some claimed substantial success, while others contradicted with evidence of failure. But the success remains a matter of debate due to lack of empirical evidence of actual empowerment of women around the world. The current study aimed to address this gap by taking a case study method. The study critically evaluates 20 cases carefully sampled to include representatives from the entire country of Bangladesh. The study demonstrates popular beliefs about microfinance often misguide even the borrowers and they start living in a fabricated feeling of empowerment, facing real challenges to achieve true empowerment in their lives. The impact of this finding is twofold; firstly there is a theoretical contribution, where the definition of women’s empowerment is proposed to be revisited considering findings from these cases. And lastly, the policy makers at governmental and non-governmental organisations, and multinational donor agencies need to revise their assessment tools for funding.

scholarly journals Improved design criterion for frictionally engaged contacts in overrunning clutches

2021 ◽  
Author(s):  
Nadine Nagler ◽  
Armin Lohrengel
Keyword(s):  
Design Process ◽  
Contact Area ◽  
Axial Load ◽  
State Of The Art ◽  
Tangential Force ◽  
Design Criterion ◽  
Hertzian Contact ◽  
Loss Of Function ◽  
Axial Loads ◽  
Improved Design

AbstractOverrunning clutches, also known as freewheel clutches, are frictionally engaged, directional clutches; they transmit torque depending on the Freewheel clutch rings’ rotation directions. The torque causes a tangential force in the Hertzian contact area. The hitherto “state-of-the-art design criterion” bases on this load situation. In practice, axial loads additionally act on the frictionally engaged Hertzian contact area. This additional axial load can cause the loss of the friction connection and so the freewheel clutch slips. This publication presents an improved design criterion for frictionally engaged contacts in freewheel clutches. It allows to consider tangential as well as axial loads during the design process. Additionally, it offers the possibility to estimate the probability of frictional engagement loss and gross slip based on the freewheel clutch’s application scenario. This publication points out how to use the improved design criterion to design freewheel clutches that are more robust against a loss of function.

scholarly journals Experimental and Numerical Study of Fracture Behavior of Rock-Like Material Specimens with Single Pre-Set Joint under Dynamic Loading

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2690
Author(s):  
Bo Pan ◽  
Xuguang Wang ◽  
Zhenyang Xu ◽  
Lianjun Guo ◽  
Xuesong Wang
Keyword(s):  
Crack Initiation ◽  
Crack Propagation ◽  
Joint Angle ◽  
Simulation Software ◽  
Dissipated Energy ◽  
Energy Structure ◽  
Joint Angles ◽  
Crack Penetration ◽  
Before And After ◽  
The Impact

The Split Hopkinson Pressure Bar (SHPB) is an apparatus for testing the dynamic stress-strain response of the cement mortar specimen with pre-set joints at different angles to explore the influence of joint attitudes of underground rock engineering on the failure characteristics of rock mass structure. The nuclear magnetic resonance (NMR) has also been used to measure the pore distribution and internal cracks of the specimen before and after the testing. In combination with numerical analysis, the paper systematically discusses the influence of joint angles on the failure mode of rock-like materials from three aspects of energy dissipation, microscopic damage, and stress field characteristics. The result indicates that the impact energy structure of the SHPB is greatly affected by the pre-set joint angle of the specimen. With the joint angle increasing, the proportion of reflected energy moves in fluctuation, while the ratio of transmitted energy to dissipated energy varies from one to the other. NMR analysis reveals the structural variation of the pores in those cement specimens before and after the impact. Crack propagation direction is correlated with pre-set joint angles of the specimens. With the increase of the pre-set joint angles, the crack initiation angle decreases gradually. When the joint angles are around 30°–75°, the specimens develop obvious cracks. The crushing process of the specimens is simulated by LS-DYNA software. It is concluded that the stresses at the crack initiation time are concentrated between 20 and 40 MPa. The instantaneous stress curve first increases and then decreases with crack propagation, peaking at different times under various joint angles; but most of them occur when the crack penetration ratio reaches 80–90%. With the increment of joint angles in specimens through the simulation software, the changing trend of peak stress is consistent with the test results.

Defining Preterm Birth and Stillbirth in the Western Pacific: A Systematic Review

2021 ◽  
pp. 101053952110260
Author(s):  
Mairead Connolly ◽  
Laura Phung ◽  
Elise Farrington ◽  
Michelle J. L. Scoullar ◽  
Alyce N. Wilson ◽  
...  
Keyword(s):  
Preterm Birth ◽  
National Level ◽  
Health Indicators ◽  
Western Pacific ◽  
World Health ◽  
Middle Income ◽  
Middle Income Countries ◽  
Definition Of ◽  
Health Organization ◽  
The Impact

Preterm birth and stillbirth are important global perinatal health indicators. Definitions of these indicators can differ between countries, affecting comparability of preterm birth and stillbirth rates across countries. This study aimed to document national-level adherence to World Health Organization (WHO) definitions of preterm birth and stillbirth in the WHO Western Pacific region. A systematic search of government health websites and 4 electronic databases was conducted. Any official report or published study describing the national definition of preterm birth or stillbirth published between 2000 and 2020 was eligible for inclusion. A total of 58 data sources from 21 countries were identified. There was considerable variation in how preterm birth and stillbirth was defined across the region. The most frequently used lower gestational age threshold for viability of preterm birth was 28 weeks gestation (range 20-28 weeks), and stillbirth was most frequently classified from 20 weeks gestation (range 12-28 weeks). High-income countries more frequently used earlier gestational ages for preterm birth and stillbirth compared with low- to middle-income countries. The findings highlight the importance of clear, standardized, internationally comparable definitions for perinatal indicators. Further research is needed to determine the impact on regional preterm birth and stillbirth rates.

Value assessment of antimicrobials and the implications for development, access, and funding of effective treatments: Australian stakeholder perspective

2020 ◽  
pp. 1-7
Author(s):  
Nadine T. Hillock ◽  
Tracy L. Merlin ◽  
Jonathan Karnon ◽  
John Turnidge ◽  
Jaklin Eliott
Keyword(s):  
Cost Effectiveness ◽  
Healthcare Resource ◽  
Economic Evaluations ◽  
Value Assessment ◽  
Antimicrobial Drugs ◽  
Policy Makers ◽  
Stakeholder Perspective ◽  
Definition Of ◽  
The Impact ◽  
Potential Use

Abstract Background The frameworks used by Health Technology Assessment (HTA) agencies for value assessment of medicines aim to optimize healthcare resource allocation. However, they may not be effective at capturing the value of antimicrobial drugs. Objectives To analyze stakeholder perceptions regarding how antimicrobials are assessed for value for reimbursement purposes and how the Australian HTA framework accommodates the unique attributes of antimicrobials in cost-effectiveness evaluation. Methods Eighteen individuals representing the pharmaceutical industry or policy-makers were interviewed. Interviews were transcribed verbatim, coded, and thematically analyzed. Results Key emergent themes were that reimbursement decision-making should consider the antibiotic spectrum when assessing value, risk of shortages, the impact of procurement processes on low-priced comparators, and the need for methodological transparency when antimicrobials are incorporated into the economic evaluation of other treatments. Conclusions Participants agreed that the current HTA framework for antimicrobial value assessment is inadequate to properly inform funding decisions, as the contemporary definition of cost-effectiveness fails to explicitly incorporate the risk of future resistance. Policy-makers were uncertain about how to incorporate future resistance into economic evaluations without a systematic method to capture costs avoided due to good stewardship. Lacking financial reward for the benefits of narrower-spectrum antimicrobials, companies will likely focus on developing broad-spectrum agents with wider potential use. The perceived risks of shortages have influenced the funding of generic antimicrobials in Australia, with policy-makers suggesting a willingness to pay more for assured supply. Although antibiotics often underpin the effectiveness of other medicines, it is unclear how this is incorporated into economic models.

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