Design criteria for exposed hydro penstocks

1978 ◽  
Vol 5 (3) ◽  
pp. 340-351 ◽  
Author(s):  
J. L. Gordon
Keyword(s):  
Quality Control ◽  
Pressure Vessel ◽  
High Strength Steel ◽  
High Strength ◽  
Design Criteria ◽  
Similar Work ◽  
Wide Range ◽  
Different Types ◽  
Control Procedures ◽  
American Society

At present there are no national codes for the design of exposed hydro-electric penstocks. Thus an engineer must either make reference to other national codes for similar work, such as the American Society of Mechanical Engineers boiler and pressure vessel code or the American Water Works Association Standard for steel water piping, or he must write his own code and is then faced with the decision of having to select design criteria that must cover a wide range of steels; different operating and waterhammer conditions; a wide range of quality control procedures used in manufacture and erection of the penstock; and different types of penstocks, isostatic where the stresses can be calculated with precision, and hyperstatic where the stress calculation is more imprecise. This paper discusses design criteria, factors of safety, and corresponding quality control procedures that can be used for either isostatic or hyperstatic penstocks using mild, intermediate, or high strength steel for penstocks supplying reaction of impulse turbines.

Structural Performance Evaluation of Built-Up Stub Steel Column with Various Steel Grades under Concentric Loading

2015 ◽  
Vol 764-765 ◽  
pp. 127-131
Author(s):  
Yang Yang ◽  
Kang Min Lee ◽  
Keun Yeong Oh ◽  
Sung Bin Hong
Keyword(s):  
Tensile Strength ◽  
High Strength Steel ◽  
Local Stability ◽  
Experimental Studies ◽  
High Strength Steels ◽  
High Strength ◽  
Design Criteria ◽  
Stability Criteria ◽  
Steel Grades ◽  
Concentric Loading

The current local stability criteria (KBC2009, AISC2010) are enacted through theoretical and experimental studies of ordinary steels, but the mechanical properties of high strength steels are different from ordinary steels. The high strength steel in the applicability of design criteria should be needed to review because of increasing market demanding for high strength steel in the high-rise and long span buildings. In this study, stub columns of H-shaped and box section with various steel grades subjected to concentric loading were investigated, and these steels were checked to the applicability of current local stability criteria. The difference between the ordinary steel and high strength steel was compared. As a result of comparison with various steel grades, most specimens were satisfied with the design criteria, but some specimens with lower tensile strength were not reached the required strength. It is considered that the uncertainty of material was the higher when the tensile strength of material was the lower.

Selection and Evaluation of High-Strength Steel for Hutton TLP Tension Leg Elements

1984 ◽  
Vol 106 (1) ◽  
pp. 32-37 ◽  
Author(s):  
M. M. Salama ◽  
J. H. Tetlow
Keyword(s):  
Corrosion Fatigue ◽  
High Strength Steel ◽  
Fatigue Behavior ◽  
High Strength ◽  
Mooring System ◽  
Test Program ◽  
The North ◽  
Extensive Evaluation ◽  
The North Sea ◽  
Control Procedures

The development of the tension leg platform (TLP) for the Hutton Field in the North Sea represents the first application of this deepwater concept. The use of vertical tension legs as the mooring system is the most novel part of the TLP design. One of the unique features of the tension legs is the use of 92.5-mm (3.64-in.) thick tubulars forged from 3 1/2 percent Ni-Cr-Mo-V high-strength steel (795 MPa (115.3 ksi) minimum yield strength) as mooring elements. Because of the importance of these elements to the survival of the TLP, the chemical composition and the steelmaking procedure were critically examined and optimized. In addition, extensive evaluation of the corrosion fatigue behavior of the steel was undertaken. This paper discusses the basis for the steel selection and specification, the results of the rigorous corrosion fatigue test program, and the assessment of the variation of properties along the length and through the thickness of full-size components. These results illustrate the suitability of the proposed high-strength steel for the mooring system application and establish confidence in both steelmaking and quality control procedures.

Development of Design Criteria for a High Pressure Vessel Construction Code

1987 ◽  
Vol 109 (2) ◽  
pp. 256-259 ◽  
Author(s):  
G. J. Mraz
Keyword(s):  
High Pressure ◽  
Pressure Vessel ◽  
High Strength Steels ◽  
High Strength ◽  
Design Criteria ◽  
Construction Methods ◽  
Shrink Fitting ◽  
Section Viii ◽  
Pressure Stress ◽  
Selection Of

Out of concern for public safety, most legal jurisdictions now require unfired pressure vessel construction to comply with the ASME Boiler and Pressure Vessel Code. Because the present two divisions of Section VIII of that Code are not well suited for high pressure design, a new division is needed [1]. The currently anticipated main design criteria of the proposed division are full plastic flow or full overstrain pressure, stress intensity in the bore, fatigue, and fracture mechanics. The rules are expected to allow better utilization of high strength steels already included in the present Section VIII. At the same time materials of even higher strength are introduced. The benefits of compressive prestress are recognized. Construction methods allowing it’s achievement, such as autofrettage, shrink fitting and wire winding are included. Reasons for selection of the criteria are given.

scholarly journals A wide range constitutive equation for medium and high strength steel

1994 ◽  
Vol 04 (C8) ◽  
pp. C8-471-C8-476 ◽  
Author(s):  
B. D. Goldthorpe ◽  
A. L. Butler ◽  
P. Church
Keyword(s):  
Constitutive Equation ◽  
High Strength Steel ◽  
High Strength ◽  
Wide Range

Mechanical Joining of Various Materials by Clinching Method

2015 ◽  
Vol 662 ◽  
pp. 205-208 ◽  
Author(s):  
Ľuboš Kaščák ◽  
Emil Spišák ◽  
Jacek Mucha
Keyword(s):  
High Strength Steel ◽  
Steel Sheet ◽  
Low Carbon Steel ◽  
Surface Preparation ◽  
High Strength ◽  
Low Carbon ◽  
Steel Sheets ◽  
Joint Properties ◽  
Wide Range ◽  
Grade Steel

Clinching is a simple, cheap and efficient method of joining that enables to join two or more sheets without any additional elements such as rivets, bolts or nuts. In addition, clinching does not require a surface preparation e.g. drilling (riveting), cleaning and roughening of the surface (adhesive boding) and other types of surface preparations (arc welding). Clinching is utilized in a wide range of applications and can be applied to different materials such as low carbon steel sheets, high-strength steel sheets, aluminium alloys, magnesium alloys. The paper presents the results of evaluation of clinched joint properties. The advanced high-strength steel sheet DP600 in combination with the drawing grade steel sheets DC06, DX51D+Z and high-strength low alloy steel sheet H220PD were used for experiments. The influence of position of the sheets relative to the punch and die of the tool on the carrying capacities of the clinched joints was observed as well. The tension test and microhardness test were used for the evaluation of clinched joint properties.

scholarly journals The Influence of Hot-Dip Galvanizing on the Mechanical Properties of High-Strength Steels

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5219
Author(s):  
Milan Šmak ◽  
Jaroslav Kubíček ◽  
Jiří Kala ◽  
Kamil Podaný ◽  
Jan Vaněrek
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Chemical Composition ◽  
Yield Strength ◽  
High Strength Steel ◽  
High Strength Steels ◽  
High Strength ◽  
Steel Members ◽  
Different Types ◽  
Standard Quality

Modern high-strength steels achieve their strength exclusively through the manufacturing process, as the chemical composition of these steels is very similar to the composition of standard-quality steels. Typically, hot-dip galvanizing is used to form a protective zinc layer on the steel parts of structures; nonetheless, the material is exposed to high temperatures during the process. With high-strength steels, this can lead to deterioration of the mechanical properties. This study aims to experimentally examine and evaluate the extent of deterioration of the mechanical properties of high-strength-steel members. The effect was studied on specimens made of three different types of steel with the yield strength ranging from 460 to 1250 MPa. For each type of steel, selected mechanical properties—yield strength, tensile strength, and hardness—were determined on specimens with and without hot-dip galvanization, and the obtained results were mutually compared. Our study shows a significant impact of the hot-dip galvanization process on the mechanical properties of some high-strength steels. With the studied types of steel, the yield strength decreased by up to 18%, the tensile strength by up to 13%, and the hardness by up to 55%.

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