The Stability of an Axially–Loaded Continuous Beam

1955 ◽  
Vol 59 (535) ◽  
pp. 506-509
Author(s):  
A. M. Dobson

The Classical method of solution of the stability of an axially–loaded continuous beam is by means of the three moments equation, using the Berry Functions, which are functions of the axial load. As the axial load approaches a value equal to the critical value for a pin–jointed beam, the Berry Functions tend to infinity, and the use of the three moments equations —(i. e. treating the end fixing moments as the independent variables)—leads to certain difficulties in the complete solution of the problem.The major difficulty lies in the question of stability. The critical value is determined by the vanishing of the determinant of the coefficients of the fixing moments in the three moments equations. This value could be found by plotting the determinant against end load (c. f. Pippard and Pritchard). However, in a problem involving a large number of bays, the calculation necessary to do this is likely to be considerable, for there may be many branches to the curve.

1955 ◽  
Vol 59 (540) ◽  
pp. 848-849 ◽  
Author(s):  
A. Bolton ◽  
J. B. B. Owen

From Mr. A. M. Dobson's Note (July 1955 Journal, page 506) which dealt with the stability of an axially loaded continuous beam, and other contacts we have had with the Aircraft Industry, it would appear that the very considerable developments of structural theory which have taken place in relation to continuous beams subjected to axial load, as employed in normal structural steel work, are not well known in aircraft stress offices. The list of references appended may then be found helpful.


2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Tony Susilo Wibowo ◽  
I Made Bagus Dwiarta

 Culinary industry competition getting tougher to make some employers continue to innovate at a restaurant for some things like menu, places, atmosphere and service that became the mainstay of the restaurant. In so doing, it needs one innovation ability of human resources quality and competence in their field. Innovation will be a reminder for consumers who feel the restaurant services and in turn will increase the revenue thus achieved profit restaurant that is optimal.The selected researchers research object was 3rd Restaurant Oriental cuisine i.e. Kapin, X O Cuisine and Paradise Dynasty which respectively have 3 and 2 branches of the restaurant. This research uses the concept of job characteristics expressed by Hackman and Oldham (1976), which are further subdivided into 5 independent variables namely a diversity of tasks, task identity, task meaningful, autonomy and feedback as well as the dependent variable turnover intention, while the analysis on research using multiple linear regression with the respondent an amount of 120 people that consists of all the employees of the restaurant. Data processing results shows that the diversity of the variable assignments and most influential task ID with a value of beta X1  0,676 and the beta X 2 of 0,538 so that these two variables have a positive and significant impact on the turnover intention because the variable is greater than 0.05 alpha. While the 3 other variables i.e  tasks meaningful, autonomy and feedback does not affect significantly to turnover intention. Keywords: Job Characteristics, Turnover intention.  


2021 ◽  
Vol 13 (3) ◽  
pp. 1326
Author(s):  
Hongfang Li ◽  
Huixiao Wang ◽  
Yaxue Yang ◽  
Ruxin Zhao

The interactions of water, energy, and food, which are essential resources for human survival, livelihoods, production, and development, constitute a water–energy–food (WEF) nexus. Applying symbiosis theory, the economic, social, and natural factors were considered at the same time in the WEF system, and we conducted a micro-level investigation focusing on the stability, coordination, and sustainability of the symbiotic units (water, energy, and food), and external environment of the WEF system in 36 prefecture-level cities across three northeastern provinces of China. Finally, we analyzed the synergistic safety and coupling coordination degree of the WEF system by the combination of stability, coordination, and sustainability, attending to the coordination relationship and influences of the external environment. The results indicated that the synergistic safety of the WEF system in three northeastern provinces need to equally pay attention to the stability, coordination, and sustainability of the WEF system, since their weights were 0.32, 0.36 and 0.32, respectively. During 2010–2016, the synergistic safety indexes of the WEF system ranged between 0.40 and 0.60, which was a state of boundary safety. In the current study, the coupling coordination degree of the WEF system fluctuated around a value of 0.6, maintaining a primary coordination level; while in the future of 2021–2026, it will decline to 0.57–0.60, dropping to a weak coordinated level. The conclusion could provide effective information for decision-makers to take suitable measures for the security development of a WEF system.


Photonics ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 70
Author(s):  
Maria Raposo ◽  
Carlota Xavier ◽  
Catarina Monteiro ◽  
Susana Silva ◽  
Orlando Frazão ◽  
...  

Thin graphene oxide (GO) film layers are being widely used as sensing layers in different types of electrical and optical sensor devices. GO layers are particularly popular because of their tuned interface reflectivity. The stability of GO layers is fundamental for sensor device reliability, particularly in complex aqueous environments such as wastewater. In this work, the stability of GO layers in layer-by-layer (LbL) films of polyethyleneimine (PEI) and GO was investigated. The results led to the following conclusions: PEI/GO films grow linearly with the number of bilayers as long as the adsorption time is kept constant; the adsorption kinetics of a GO layer follow the behavior of the adsorption of polyelectrolytes; and the interaction associated with the growth of these films is of the ionic type since the desorption activation energy has a value of 119 ± 17 kJ/mol. Therefore, it is possible to conclude that PEI/GO films are suitable for application in optical fiber sensor devices; most importantly, an optical fiber-based interrogation setup can easily be adapted to investigate in situ desorption via a thermally stimulated process. In addition, it is possible to draw inferences about film stability in solution in a fast, reliable way when compared with the traditional ones.


2005 ◽  
Vol 2005 (23) ◽  
pp. 3727-3737 ◽  
Author(s):  
Jitender Singh ◽  
Renu Bajaj

Effect of an axially applied magnetic field on the stability of a ferrofluid flow in an annular space between two coaxially rotating cylinders with nonaxisymmetric disturbances has been investigated numerically. The critical value of the ratioΩ∗of angular speeds of the two cylinders, at the onset of the first nonaxisymmetric mode of disturbance, has been observed to be affected by the applied magnetic field.


Author(s):  
Swaminathan Ganesan ◽  
Sampath Vedamanickam

In this study, the influence of upper cycle temperature (maximum temperature in a cycle) and the magnitude of applied stress on the functional properties of an SMA during partial thermomechanical cycling has been studied. A near-equiatomic NiTi SMA was chosen and tested under different upper cycle temperatures (between martensite finish (Mf) and austenite finish (Af) temperatures) and stress level (below and above the yield strength of the martensite). The upper cycle temperature was varied by controlling the magnitude of the current supply. The results show that a raise in the upper cycle temperature causes the permanent strain to increase and also lowers the stability. However, decreasing the stress imposed to a value lower than the yield strength of the martensite improves cyclic stability. The upper cycle temperature was found to influence the crack nucleation, whereas the applied stress level the crack propagation during partial thermomechanical cycling of SMAs. Therefore, decreasing the upper cycle temperature as well as the magnitude of stress applied to lower than the yield stress of martensite have been found to be suitable strategies for increasing the lifespan of SMA-based actuators during partial thermomechanical cycling.


2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Van Binh Phung ◽  
Anh Tuan Nguyen ◽  
Hoang Minh Dang ◽  
Thanh-Phong Dao ◽  
V. N. Duc

The present paper analyzes the vibration issue of thin-walled beams under combined initial axial load and end moment in two cases with different boundary conditions, specifically the simply supported-end and the laterally fixed-end boundary conditions. The analytical expressions for the first natural frequencies of thin-walled beams were derived by two methods that are a method based on the existence of the roots theorem of differential equation systems and the Rayleigh method. In particular, the stability boundary of a beam can be determined directly from its first natural frequency expression. The analytical results are in good agreement with those from the finite element analysis software ANSYS Mechanical APDL. The research results obtained here are useful for those creating tooth blade designs of innovative frame saw machines.


Author(s):  
Mohammed F. Daqaq

Driven by the study of Leland and Wright [1], this manuscript delves into the qualitative understanding of energy harvesting using axially-loaded beams. Using a simple nonlinear electromechanical model and the method of multiple scales, we study the general nonlinear physics of energy harvesting from a piezoelectric beam subjected to static axial loading and traversal dynamic excitation. We obtain analytical expressions for the steady-state response amplitude, the voltage drop across a resistive load, and the output power. We utilize these expression to study the effect of the axial loading on the overall nonlinear behavior of the harvester. It is demonstrated that, in addition to the ability of tuning the harvester to the excitation frequency via axial load variations, the axial load aids in i) increasing the electric damping in the system thereby enhancing the energy transfer from the beam to the electric load, ii) amplifying the effect of the external excitation on the structure, and hence, increases the steady-state response amplitude and output voltage, and iii) increasing the bandwidth of the harvester by enhancing the effective nonlinearity of the system.


2014 ◽  
Vol 78 (7) ◽  
pp. 1671-1675 ◽  
Author(s):  
Adam J. Roper ◽  
Peter Leverett ◽  
Timothy D. Murphy ◽  
Peter A. Williams

AbstractSynthesis and solubility studies of onoratoite have been undertaken to determine the role of this rare secondary phase in the immobilization of Sb and the conditions responsible for its formation in the supergene zone. Solubility studies were undertaken at 298.15 K. A value of ΔGfθ (Sb8O11Cl2, s, 298.15 K) = –2576 ±12 kJ mol–1 was derived. Calculations involving sénarmontite, Sb2O3, klebelsbergite, Sb4O4SO4(OH)2 and schafarzikite, FeSb2O4, show that onoratoite is a thermodynamically stable phase only at negligible activities of SO42–(aq) and low activities of Fe2+(aq), at low pH and very high activities of Cl–(aq). This explains why onoratoite is such a rare secondary phase and why it cannot exert any significant influence on the dispersion of Sb in the supergene environment.


2018 ◽  
Vol 5 (1) ◽  
pp. 65
Author(s):  
Ita Rakhmawati ◽  
Suhadi Suhadi

The crisis in 1997 is the image of the high rise in inflation in Indonesia. The phenomenon of inflation when it reached 82.40% (Anas, 2006). The early mid-1998 also experienced a weakening of the rupiah against the dollar. Condition stable economy is the desire of each country in comparison with the state of the economy has always fluctuated. Economic stability will create an atmosphere conducive economy. stable climatic conditions in the expected level of welfare is the purpose in each country. One of the efforts to maintain economic stability is through monetary policy. For example, with economic growth, maintain price stability (inflation), the achievement of the balance of payments and the reduction of unemployment (Natsir, 2008). The stability of the financial system of a country of which reflected their price stability, in the sense that there are a great price that can be harmful to society, both consumers and manufacturers that will damage the joints of the economy. However, the implementation of the policy, Bank Indonesia as the monetary authority uses monetary variables such as interest rates and the money supply to cope with economic shocks such as inflation. Besides the need for the government’s role in maintaining the rupiah to avoid turmoil in the economy. The importance of inflation control based on the consideration that the high inflation and unstable negative impact on socio-economic conditions of society. Among the high inflation will cause a decline in the real income of the community so that the standard of living of the people down and eventually make everyone, especially the poor get poorer. From one of the effects of inflation are so wide will impact people’s demands to meet the needs of more and more difficult. Their continuousprice increases being offset by rising income of the communities, it can make sure the Indonesian state would worsen. As a result many people’s needs can not be met, so many things that must be met by way of credit. The number of community needs that must be met will cause world of opportunities for banks to offer credit readily available to meet the needs. The third object of research above (inflation, poverty, and credit) does affect the stability of the financial system? In this study using secondary data from the Badan Pusat Statistik (BPS) and Bank Indonesia (BI) with time series data from the years 2007-2015. The process of data analysis was performed using OLS regression with Eviews 8.0. Based on research, if only partial test of the poverty variable significantly affect the stability of the financial system amounted to 2,023 with α = 10%. Meanwhile, two other variables (inflation and poverty) is not significant to the stability of the financial systemMeanwhile, two other variables (inflation and poverty) is not significant to the stability of the financial system. While the value of R-Square (0.629900), indicating that the three independent variables / free consisting of inflation, poverty and credit simultaneously have the effect that make the stabilization of the financial system increases or decreases. That is jointly independent variables (inflation, poverty and loans) contributed / effect of 62.9% against the stability of the financial system. The rest is the influence of other factors beyond the three independent variables studied.


Sign in / Sign up

Export Citation Format

Share Document