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Comparison of Punching Shear Design in Finland According to the Current and the Former Method

Abstract

In the beginning of 2017 the design method for punching shear in Finland was changed. The method presented in Eurocode 2 was adopted with some nationally determined parameters and rules. During 2016 and 2017 computational analyses were conducted to compare the previous national design method and the new one. Comparison setups were created in which different parameters were varied. The results were presented the predicted punching resistances differ differences are significant and can be almost 60% in some cases.

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Investigation of Milling of Carbon Fiber Reinforced Plastic

Abstract

The use of fiber-reinforced plastics has increased significantly in the past decades. Consequently, the demand for finishing and machining of such materials has also escalated. During machining, the fiber-reinforced materials exhibit machining problems dissimilar to the problems of metals. These are fiber pull-out, fiber breakage in the cutting zone, matrix smearing and delamination. The purpose of this experiment is to investigate the characteristics of the resultant force (Fe) dur-ing the milling of carbon fiber reinforced plastic as a function of input machining parameters. For the force measurements, CFR with perpendicular (0°-90°) fiber orientation was machined. The experimental design involved the central composite design method. To analyze and evaluate the measurements, we applied the response surface methodology.

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Meso Mechanical Study of Cracking Process in Concrete Subjected to Tensile Loading

Materials, Ed I Fernandes, 2007. 24. RILEM TC 187-SOC: Experimental determination of the stress-crack opening curve for concrete in tension: Final report , May 2007. 25. RILEM TC 162-TDF: Test and design methods for steel fibre reinforced concrete: Uni-axial tension test for steel fibre reinforced concrete. Materials and Structures , Vol. 34, 2001, pp. 3-6. 26. van Mier J G M: Concrete Fracture, a Multiscale Approach, CRC Press, 2012. Nordic Concrete Research – Publ. No. NCR 59 – ISSUE 2 / 2018 – Article 3, pp. 31-44

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Effect of sintering parameters using the central composite design method, electronic structure and physical properties of yttria-partially stabilized ZrO2 commercial ceramics

Abstract

In this work, the effect of sintering parameters on electronic structure and physical properties of yttria-partially stabilized ZrO2 (YPSZ) commercial ceramics has been studied using the central composite design (CCD) method. The CCD method allows using empirical modelling with better fitting, by considering the interaction between both factors. Different temperature ranges and sintering times for processing of YPSZ ceramics have been used in order to evaluate the grain growth, hardness and volumetric shrinkage by the CCD method. X-ray diffraction patterns and Rietveld refinement data indicate that non-sintered YPSZ ceramics exhibits two phases related to tetragonal and monoclinic structures, while the sintered YPSZ ceramics exhibits a single phase related to a tetragonal structure. Moreover, the monoclinic structure presents zirconium (Zr) atoms coordinated to seven oxygen (O) atoms, while in the tetragonal structure Zr atoms are coordinated to eight O atoms. Field emission scanning electron microscopy images were employed to monitor the sintering and growth process. In addition, the response surfaces obtained from calculations presented the effect of thermal and kinetic variables on the physical properties such as average grain size, volumetric shrinkage and hardness of YPSZ ceramics.

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Study of the Influence of Fibres Type and Dosage on Properties of Concrete for Airport Pavements

Abstract

The paper follows the potential practice of fiber reinforced concrete (FRC) as a solution for airport`s runway pavements, in order to increase the bearing strength, resulting in decreasing the height of the concrete layer that is currently used.

Experimentally, the study focuses on the properties of fiber reinforced Portland cement concrete using 3 different percentages (0.5%, 1% and 1.5% of the concrete volume) and 4 different types of fiber (for 1% percentage – hooked steel fiber 50 mm length, hooked steel fiber 30 mm length, crimped steel fiber 30 mm length and polypropylene fiber 50 mm lenght), using as reference a plain concrete with 5 MPa flexural strength.

More exactly, the study presents the change in compressive and flexural strength, shrinkage, thermal expansion factor, elastic modulus and Poisson`s ratio over fiber type and dosage.

For the highest performance concrete (7 MPa flexural strength), it has been made a study using two methods for rigid airport pavements design (general method and optimized method), and one method for evaluation of bearing strength (ACN – PCN method), which is compared to a plain 5 MPa concrete. Furthermore, the decrease in the slab`s thickness proportionally to the growth of the flexural strength is emphasized by evaluating the slab`s height for a high performance 9 MPa concrete using both design methods.

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Effect of settlement of foundations on the failure risk of the bottom of cylindrical steel vertical tanks for liquids

). Comparison of design methods for a tank-bottom annular plate and concrete ringwall. International Journal of Pressure Vessels and Piping 77, p. 511-517. 10.1016/S0308-0161(00)00055-7 Wu T.Y. Liu G.R. 2000 Comparison of design methods for a tank-bottom annular plate and concrete ringwall International Journal of Pressure Vessels and Piping 77 511 517 [6] Lenzi M., Campana P. (2008). Ovalization of Steel Storage Tanks as a Result of Differential Settlements Structural Engineering International , Volume 18, No. 4. Lenzi M. Campana P. 2008

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Setup of axial bearing capacity of open ended tubular steel piles driven in sand

. Jardine R.J. Standing J.R. 1999 Pile load testing performed for HSE cyclic loading study at Dunkirk, France. Vol. 1. UK. Health and Safety Executive London, UK Offshore Technology Report OTO 2000 007 [13] Jardine, R., Chow, F., Overy, R., Standing, J., 2005. ICP design methods for driven piles in sands and clays. Thomas Telford. Jardine R. Chow F. Overy R. Standing J. 2005 ICP design methods for driven piles in sands and clays Thomas Telford [14] Jardine, R.J., Standing, J.R., Chow, F.C., 2006. Some observations of the effects of

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Modelling the time-dependent behaviour of soft soils

drawbacks. Time-dependent behaviour of soft soils should be incorporated in the design reasonably. Each practical case involving organic soils should be thoroughly investigated. Finally, the proper design methods, considering safe and economic aspects, should be chosen. References [1] den Haan, E.J., Feddema, A. (2013). Deformation and strength of embankments on soft Dutch soil. Geotechnical Engineering 166, 239‑252. den Haan E.J. Feddema A. 2013 Deformation and strength of embankments on soft Dutch soil Geotechnical Engineering 166 239 252

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On Some Methods in Safety Evaluation in Geotechnics

Abstract

The paper demonstrates how the reliability methods can be utilised in order to evaluate safety in geotechnics. Special attention is paid to the so-called reliability based design that can play a useful and complementary role to Eurocode 7. In the first part, a brief review of first- and second-order reliability methods is given. Next, two examples of reliability-based design are demonstrated. The first one is focussed on bearing capacity calculation and is dedicated to comparison with EC7 requirements. The second one analyses a rigid pile subjected to lateral load and is oriented towards working stress design method. In the second part, applications of random field to safety evaluations in geotechnics are addressed. After a short review of the theory a Random Finite Element algorithm to reliability based design of shallow strip foundation is given. Finally, two illustrative examples for cohesive and cohesionless soils are demonstrated.

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Wing and Engine Sizing by Using the Matching Plot Technique

Abstract

The research focuses on the development of an Unmanned Aircraft System. For design purposes, a rather new design method called Systems Engineering Approach is used. Development of the whole system takes much time and effort. This paper contains a concise description of the research on the preliminary development phase of Unmanned Aircraft System air vehicle. The method was first introduced by NASA and later developed by authors of books on aircraft design used for information purposes for design and are mentioned in references. The obtained results are rather realistic and promising for further design process. The method is simple and understandable, and it should be used more often to make it more steady and reliable.

Open access