scholarly journals Review on Local Buckling of Hollow Box FRP Profiles in Civil Structural Applications

Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4159
Author(s):  
Mohammad Alhawamdeh ◽  
Omar Alajarmeh ◽  
Thiru Aravinthan ◽  
Tristan Shelley ◽  
Peter Schubel ◽  
...  
Keyword(s):  
Local Buckling ◽  
Cost Effective ◽  
Design Parameters ◽  
Structural Level ◽  
Research Gaps ◽  
Design Standards ◽  
Outer Corner ◽  
Open Section ◽  
Structural Applications ◽  
Current Design

Hollow box pultruded fibre-reinforced polymers (PFRP) profiles are increasingly used as structural elements in many structural applications due to their cost-effective manufacturing process, excellent mechanical properties-to-weight ratios, and superior corrosion resistance. Despite the extensive usage of PFRP profiles, there is still a lack of knowledge in the design for manufacturing against local buckling on the structural level. In this review, the local buckling of open-section (I, C, Z, L, T shapes) and closed-section (box) FRP structural shapes was systematically compared. The local buckling is influenced by the unique stresses distribution of each section of the profile shapes. This article reviews the related design parameters to identify the research gaps in order to expand the current design standards and manuals of hollow box PFRP profiles and to broaden their applications in civil structures. Unlike open-section profiles, it was found that local buckling can be avoided for box profiles if the geometric parameters are optimised. The identified research gaps include the effect of the corner (flange-web junction) radius on the local buckling of hollow box PFRP profiles and the interactions between the layup properties, the flange-web slenderness, and the corner geometry (inner and outer corner radii). More research is still needed to address the critical design parameters of layup and geometry controlling the local buckling of pulwound box FRP profiles and quantify their relative contribution and interactions. Considering these interactions can facilitate economic structural designs and guidelines for these profiles, eliminate any conservative assumptions, and update the current design charts and standards.

scholarly journals Calculation features of wall panels with monolithic cement bond of layers in the stages of installation, transportation and maintenance

Vestnik MGSU ◽  
2019 ◽  
pp. 367-375 ◽  
Author(s):  
Elena A. Korol’ ◽  
Marina N. Berlinova
Keyword(s):  
Middle Layer ◽  
Structural Features ◽  
Design Parameters ◽  
Competitive Advantages ◽  
Design Standards ◽  
Wall Panels ◽  
Multilayer Wall ◽  
Current Design ◽  
Infinite Variety ◽  
Construction Practice

Introduction. When building residential, public and administrative buildings of various spatial structural designs (monolithic, precast-monolithic, precast, etc.), it is common practice to design self-sustaining (non-structural) outer walls within a storey. Developing and using new design and fabrication solutions of multilayer industrial-made wall panels in modern construction practice makes actual the issue of improving methods of their calculation in different stages of maintenance and under various sorts and combinations of loads and effects. However, there is an infinite variety of possible loading levels in practice and, therefore, the same variety of design approaches would be required. This is obviously unacceptable for engineering calculations, hence it is necessary to provide a monolithic matrix bond of layers, both technologically and structurally, which can provide a generalized approach to the calculation of multilayer enclosing structures in accordance with current design standards. Materials and methods. The article describes structural features of a multilayer wall panel made of structural concrete with the middle layer of concrete with low thermal conductivity and monolithic bond of layers. These features have an influence on creation of a design model and a calculation procedure in the stages of transportation, installation and maintenance. Results. The article has examined the structures described above in the sense of design parameters that provide their competitive advantages in strength and maintenance as compared with conventional mass-built enclosures. Conclusions. The studies demonstrate that when combining loads of force and non-force character, stresses in the considered structure do not exceed allowable values in all the stages what proves the prospects of using the multilayer panels with monolithic bond of layers for erection of various-purpose frame-panel buildings.

scholarly journals RESILIENCE TO EXTREME EVENTS

2012 ◽  
Vol 1 (33) ◽  
pp. 1 ◽  
Author(s):  
Lesley Ewing ◽  
Costas Synolakis
Keyword(s):  
Extreme Events ◽  
Disaster Response ◽  
Extreme Event ◽  
Cost Effective ◽  
Scenario Development ◽  
Design Standards ◽  
Natural Systems ◽  
Cost Effective Approach ◽  
Current Design ◽  
Management Approaches

Coastal communities rely upon a range of protection elements, both constructed and natural, for resilience. Although extreme events might be assumed to be quite rare, given the level of protection that is available for many communities, extreme events can happen every few decades. Resilience of protection will diminish over time unless the elements are maintained, or in the case of natural systems, given the resources to expand and grow. As a result, communities with well-balanced and diverse resilience might find that resilience decreases with time. Extreme events or the consideration of extreme events through contingency planning and scenario development, provide valuable insights into the weaknesses in any resilience effort and help identify steps to enhance resilience for a broad spectrum of future conditions. This paper provides a definition for resilience that covers the pre-disaster conditions, disaster response and post-disaster recovery. It examines resilience of various protection management approaches for a hypothetical community. While a do-nothing approach can be the most cost-effective approach if there is no risk that an extreme event might happen, for situations where extreme events are possible, the resilience of a community can be enhanced by a modified status quo approach in which elements are maintained regularly and rebuilt to the current design standards when they experience significant damage.

Electrochemical cleaning of soils with different concentrations of oil pollution using a single source of electrical voltage

2020 ◽  
Vol 10 (6) ◽  
pp. 674-680
Author(s):  
Nikolay S. Shulaev ◽  
◽  
Valeriya V. Pryanichnikova ◽  
Ramil R. Kadyrov ◽  
Inna V. Ovsyannikova ◽  
...  
Keyword(s):  
Contaminated Soils ◽  
Oil Pollution ◽  
Cost Effective ◽  
Electrical Energy ◽  
Design Parameters ◽  
Technological Infrastructure ◽  
Chemical Reagents ◽  
Electrode Space ◽  
Soil Excavation ◽  
Interelectrode Resistance

The most essential scientifific and practical task in the area of ecological safety of pipelines operation is the development and improvement of methods of purifification and restoration of oil-contaminated soils. One of the most effificient and cost effective methods is electrochemical purifification, that does not require the use of expensive chemical reagents and soil excavation. However, the consideration of non-uniform contamination of various soil sections is required. The article examines the features of the organization and technological infrastructure for electrochemical purifification of non-uniformly contaminated soils when using a single electrical energy source, a method for calculating the design parameters of the corresponding installation is proposed. Effificient purifification of non-uniformly contaminated soil when using a specifified voltage is possible through the use of different-sized electrodes. For each soil type, the amount of transmitted electric charge required for soil purifification is determined by the concentration of the contaminant. Allocation of cathodes and anodes as parallel batteries and their connection using individual buses is an effective and energy-effificient solution, since an almost-uniform electric fifield is created in an inter-electrode space, thus allowing the reduction of the interelectrode resistance of the medium.

FERRIUM M54

Alloy Digest ◽  
2018 ◽  
Vol 67 (9) ◽  
Keyword(s):  
Fracture Toughness ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
High Resistance ◽  
High Strength ◽  
Cost Effective ◽  
High Fracture Toughness ◽  
High Fracture ◽  
Structural Applications ◽  
Resistance To Stress

Abstract Ferrium M54 was designed to create a cost-effective, ultra high-strength, high-fracture toughness material with a high resistance to stress-corrosion cracking for use in structural applications. This datasheet provides information on composition, hardness, and tensile properties as well asfatigue. Filing Code: SA-822. Producer or source: QuesTek Innovations, LLC.

Front steering design guidelines formulation for e-scooters considering the influence of sitting and standing riders on self-stability and safety performance

2021 ◽  
pp. 095440702199217
Author(s):  
Milan Paudel ◽  
Fook Fah Yap
Keyword(s):  
Preventive Measures ◽  
Recent Trend ◽  
Dynamic Performance ◽  
Design Guidelines ◽  
Safety Performance ◽  
Design Parameters ◽  
Single Track ◽  
Standing Posture ◽  
Last Mile ◽  
Current Design

E-scooters are a recent trend and are viewed as a sustainable solution to ease the first and last mile problem in modern transportation. However, an alarming rate of accidents, injuries, and fatalities have caused a significant setback for e-scooters. Many preventive measures and legislation have been put on the e-scooters, but the number of accidents and injuries has not reduced considerably. In this paper, the current design approach of e-scooters has been analyzed, and the most common range of design parameters have been identified. Thereafter, validated mathematical models have been used to quantify the performance of e-scooters and relate them with the safety aspects. Both standing and seated riders on e-scooters have been considered, and their influence on the dynamic performance has been analyzed and compared with the standard 26-in wheel reference safety bicycle. With more than 80% of the accidents and injuries occurring from falling or colliding with obstacles, this paper tries to correlate the dynamics of uncontrolled single-track vehicles with the safety performance of e-scooters. The self-stability, handling, and braking effect have been considered as major performance matrices. The analysis has shown that the current e-scooter designs are not as stable as the reference safety bicycle. Moreover, these e-scooters have been found unstable within the most common range of legislated riding velocity. The results corroborate with the general perception that the current designs of e-scooters are less stable, easy to lose control, twitchy, or wobbly to ride. Furthermore, the standing posture of the rider on the e-scooter has been found dangerous while braking to avoid any disturbances such as potholes or obstacles. Finally, the front steering design guidelines have been proposed to help modify the current design of e-scooters to improve the dynamic performance, hence the safety of the e-scooter riders and the surroundings.

Analytic Optimization of Cost Effective Thermoelectric Generation on Top of Rankine Cycle

2013 ◽  
Author(s):  
Kazuaki Yazawa ◽  
Yee Rui Koh ◽  
Ali Shakouri
Keyword(s):  
Steam Turbine ◽  
Fuel Efficiency ◽  
Cost Effective ◽  
Rankine Cycle ◽  
Energy Conversion Efficiency ◽  
Design Parameters ◽  
Steam Temperature ◽  
Combined System ◽  
Fuel Consumption Rate ◽  
The Impact

Thermoelectric (TE) generators have a potential advantage of the wide applicable temperature range by a proper selection of materials. In contrast, a steam turbine (ST) as a Rankine cycle thermodynamic generator is limited up to more or less 630 °C for the heat source. Unlike typical waste energy recovery systems, we propose a combined system placing a TE generator on top of a ST Rankine cycle generator. This system produces an additional power from the same energy source comparing to a stand-alone steam turbine system. Fuel efficiency is essential both for the economic efficiency and the ecological friendliness, especially for the global warming concern on the carbon dioxide (CO2) emission. We report our study of the overall performance of the combined system with primarily focusing on the design parameters of thermoelectric generators. The steam temperature connecting two individual generators gives a trade-off in the system design. Too much lower the temperature reduces the ST performance and too much higher the temperature reduces the temperature difference across the TE generator hence reduces the TE performance. Based on the analytic modeling, the optimum steam temperature to be designed is found near at the maximum power design of TE generator. This optimum point changes depending on the hours-of-operation. It is because the energy conversion efficiency directly connects to the fuel consumption rate. As the result, physical upper-limit temperature of steam for ST appeared to provide the best fuel economy. We also investigated the impact of improving the figure-of-merit (ZT) of TE materials. As like generic TE engines, reduction of thermal conductivity is the most influential parameter for improvement. We also discuss the cost-performance. The combined system provides the payback per power output at the initial and also provides the significantly better energy economy [$/KWh].

Ultrasonic Cavitation Based Processing of Metal Matrix Nanocomposites: An Overview

2014 ◽  
Vol 1042 ◽  
pp. 58-64 ◽  
Author(s):  
Santanu Sardar ◽  
Santanu Kumar Karmakar ◽  
Debdulal Das
Keyword(s):  
Mass Production ◽  
Metal Matrix ◽  
Cost Effective ◽  
Ultrasonic Cavitation ◽  
Basic Principles ◽  
Metal Matrix Nanocomposites ◽  
Microstructural Parameters ◽  
Structural Applications ◽  
Critical Issues ◽  
Matrix Nanocomposites

Metal matrix nanocomposites (MMNCs) have emerged as an important class of materials for structural applications specifically in the automobile and aerospace sectors; however, development of cost effective mass production technique of MMNCs with requisite operational and geometrical flexibilities is still a great challenge. Focused research in the last decade has highlighted that ultrasonic cavitation based processing is the most promising method for manufacturing of MMNCs with nearly uniform distribution of nanoparticles, having added advantage of being a liquid-phase route. This article presents an overview on the basic principles and recent advances in the ultrasonic cavitation based processing of MMNCs with a particular emphasis on identifying relationships amongst processing variables, microstructural parameters and mechanical properties. Critical issues of MMNCs fabrication are discussed.

Qualitative Knowledge and Manufacturing Considerations in Multidisciplinary Structural Optimization of Hybrid Material Structures

2006 ◽  
Vol 10 ◽  
pp. 143-152 ◽  
Author(s):  
Martin Huber ◽  
Horst Baier
Keyword(s):  
Hybrid Material ◽  
Optimization Problem ◽  
Fuzzy Rule ◽  
Optimal Designs ◽  
Design Parameters ◽  
Optimization Approach ◽  
Structural Level ◽  
Design Problems ◽  
Qualitative Knowledge ◽  
Typical Design

An optimization approach is derived from typical design problems of hybrid material structures, which provides the engineer with optimal designs. Complex geometries, different materials and manufacturing aspects are handled as design parameters using a genetic algorithm. To take qualitative information into account, fuzzy rule based systems are utilized in order to consider all relevant aspects in the optimization problem. This paper shows results for optimization tasks on component and structural level.

Analytical Derivatives Technology for Parametric Shape Design and Analysis in Structural Applications

2006 ◽  
Author(s):  
Srikanth Akkaram ◽  
Jean-Daniel Beley ◽  
Bob Maffeo ◽  
Gene Wiggs
Keyword(s):  
Sensitivity Analysis ◽  
Finite Element ◽  
Automatic Differentiation ◽  
Thermal Response ◽  
Aircraft Engine ◽  
Design Parameters ◽  
Shape Design ◽  
Computer Simulation Model ◽  
Structural Applications ◽  
Analytical Derivatives

The ability to perform and evaluate the effect of shape changes on the stress, modal and thermal response of components is an important ingredient in the ‘design’ of aircraft engine components. The classical design of experiments (DOE) based approach that is motivated from statistics (for physical experiments) is one of the possible approaches for the evaluation of the component response with respect to design parameters [1]. Since the underlying physical model used for the component response is deterministic and understood through a computer simulation model, one needs to re-think the use of the classical DOE techniques for this class of problems. In this paper, we explore an alternate sensitivity analysis based technique where a deterministic parametric response is constructed using exact derivatives of the complex finite-element (FE) based computer models to design parameters. The method is based on a discrete sensitivity analysis formulation using semi-automatic differentiation [2,3] to compute the Taylor series or its Pade equivalent for finite element based responses. Shape design or optimization in the context of finite element modeling is challenging because the evaluation of the response for different shape requires the need for a meshing consistent with the new geometry. This paper examines the differences in the nature and performance (accuracy and efficiency) of the analytical derivatives approach against other existing approaches with validation on several benchmark structural applications. The use of analytical derivatives for parametric analysis is demonstrated to have accuracy benefits on certain classes of shape applications.

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