Stability of Sloped Soil Embankment for Seismic and Tidal Load Combination

2021 ◽  
pp. 157-177
Author(s):  
Amritansh Mishra ◽  
A. Trivedi
Keyword(s):  
Load Combination

A reformulation of the stochastic load combination problem

2021 ◽  
Vol 91 ◽  
pp. 102094
Author(s):  
Mahesh D. Pandey ◽  
J.A.M. van der Weide ◽  
N. Manzana
Keyword(s):  
Load Combination ◽  
Combination Problem ◽  
Stochastic Load

Numerical and Experimental Investigation of Heat Transfer Enhancement Using Heat Pipes for Electronic Cooling

2018 ◽  
Author(s):  
Ning Zhang ◽  
Pankaj R. Chandra ◽  
Ryan Robledo ◽  
Sree Harsha Balijepalli
Keyword(s):  
Heat Transfer ◽  
Heat Pipes ◽  
Copper Plate ◽  
Heat Sinks ◽  
Modern World ◽  
Processing Unit ◽  
Maximum Heat ◽  
Central Processing ◽  
Load Combination ◽  
Maximum Heat Transfer

Computers are crucial to nearly every endeavor in the modern world. Some computers, particularly those used in military applications, are required to endure extreme conditions with limited maintenance and few parts. Units such as these will hereafter be referred to as “rugged computers.” This series of experiments aims to produce improvements to rugged computers currently in service. Using heat pipes and finned heat sinks on an enclosed box, a computer’s Central Processing Unit (CPU) is able to reject heat without suffering contamination from unforgiving environments. A modular prototype was designed to allow for three distinct cases; a case with no heat pipes and fins, a cast with heat-pipes mounted internally with exterior fins and a case with heat-pipes extended externally with exterior fins. Each case was tested at three different heat loads, with a copper plate heated by a silicone heat strip simulating the heat load generated by a CPU. Each case/load combination was run many times to check for repeatability. The aim of this research is to discover the ideal case for maximum heat transfer from the CPU to the external environment. In addition to the experiments, numerical simulation of these modular prototypes with different designs of heat pipes were conducted in this research. Creating an accurate model for computer simulations will provide validation for the experiments and will prove useful in testing cases not represented by the modular prototype. The flow and heat transfer simulations were conducted using Autodesk CFD. The aim here is to create a model that accurately reflects the experimentally-verified results from the modular prototype’s cases and loads, thereby providing a base from whence further designs can branch off and be simulated with a fair degree of accuracy.

Load Combination for Fatigue Analysis of Ship Structures

2004 ◽  
Author(s):  
Yung S. Shin ◽  
Booki Kim ◽  
Alexander J. Fyfe
Keyword(s):  
Bending Moment ◽  
Linear Summation ◽  
Load Combination ◽  
Longitudinal Stiffeners ◽  
Stress Components ◽  
Tank Pressure ◽  
Wave Induced ◽  
Vertical Bending Moment ◽  
Oil Tanker

A methodology for calculating the correlation factors to combine the long-term dynamic stress components of ship structure from various loads in seas is presented. The methodology is based on a theory of a stationary ergodic narrow-banded Gaussian process. The total combined stress in short-tem sea states is expressed by linear summation of the component stresses with the corresponding combination factors. This expression is proven to be mathematically exact when applied to a single random sea. The long-term total stress is similarly expressed by linear summation of component stresses with appropriate combination factors. The stress components considered here are due to wave-induced vertical bending moment, wave-induced horizontal bending moment, external wave pressure and internal tank pressure. For application, the stress combination factors are calculated for longitudinal stiffeners in cargo and ballast tanks of a crude oil tanker at midship section. It is found that the combination factors strongly depend on wave heading and period in the short-term sea states. It is also found that the combination factors are not sensitive to the selected probability of exceedance level of the stress in the long-term sense.

Assessment of landslide hazard under combined loading

2003 ◽  
Vol 40 (4) ◽  
pp. 821-829 ◽  
Author(s):  
Tien H Wu
Keyword(s):  
Pore Pressure ◽  
Failure Probability ◽  
Threshold Value ◽  
Landslide Hazard ◽  
Combined Loading ◽  
Rational Approach ◽  
Root Reinforcement ◽  
Load Combination ◽  
Time Period ◽  
A Site

A method for assessing landslide hazard under combined loading is described. The loads are considered as pulses that occur randomly in time. The method accounts for the rate of occurrence and the duration of the loads and calculates the rate of coincidence of two or more loads. This is used to calculate the failure probability, which is equal to the probability that the load combination will exceed a threshold value during a given time period. The method was applied to a site in the Cascade Mountains of Washington. The loads considered include those as a result of gravity, pore pressure from infiltration of rainfall plus snowmelt, loss of root reinforcement through fire or logging, and earthquakes. The example demonstrates a rational approach that accounts for the properties of the loads and the different loading conditions that may be expected.Key words: earthquake, failure probability, landslide hazard, load coincidence, load combination, pore pressure, root reinforcement.

Perbaikan dan Perkuatan Fondasi Tiang Bor pada Bangunan Gedung Perkuliahan dengan Penambahan Tiang Pancang Bulat

2021 ◽  
Vol 1 (2) ◽  
pp. 55-60
Author(s):  
Annisa Junaid
Keyword(s):  
Pile Driving ◽  
Integrity Test ◽  
Test Analysis ◽  
Bearing Strength ◽  
Bored Pile ◽  
Load Combination ◽  
Adjacent Building ◽  
Pile Type ◽  
Pile Integrity ◽  
Sudden Collapse

Fondasi harus dibangun di atas tanah keras agar bangunan tetap stabil dan kokoh. Memastikan kekuatan fondasi adalah upaya dini untuk mencegah sudden collapse pada bangunan di kemudian hari. Penelitian ini dilakukan untuk mengetahui kuat dukung tanah pada ujung tiang fondasi dan mengamati sejauh apa kerusakan beton tiang bor pada bangunan yang baru masih dalam tahap pembangunan fondasi. Data penelitian diperoleh dari hasil pengujian PDA (Pile Driving Analyzer) dan PIT (Pile Integrity Test) pada fondasi bangunan jenis bored pile D80. Pada gedung yang berdekatan, yang dikerjakan dengan sistem yang sama dan menggunakan spun pile D50. Data kuat dukung ultimate hasil manometer alat uji hidraulik 175 ton untuk pile D50. Dari analisis uji PDA, diperoleh nilai kuat dukung ijin rata-rata tiang bor adalah 70,25 ton (51%). Analisis ulang terhadap kombinasi beban menghasilkan tambahan spun pile di 44 titik. Pada beton bored pile yang mengalami kerusakan, dilakukan perbaikan seperti penambahan cor pada lapisan luar (concrete-jacketing) untuk menutupi lapisan tulangan yang terekspos, dan penambahan tulangan terpisah di sisi dalam beton untuk antisipasi bila tulangan luar rusak akibat korosi.The foundation must be placed on hard rock so that the building remains stable and solid. Thus, ensuring the strength of the foundation is an early effort to prevent sudden collapse of the building in the future. This research was conducted to determine the bearing strength of the soil at the ends of the foundation piles and to observe the extent of the damage to the drill pile concrete in the new building which is still in the foundation construction stage. The research data were obtained from the results of PDA (Pile Driving Analyzer) and PIT (Pile Integrity Test) testing on the foundation of the bored pile type D80 building. The adjacent building is being worked on with the same system and using a D50 spun pile. With the ultimate bearing strength data, the results of the hydraulic tool manometer = 175 tons for D50 piles. PDA test analysis obtained the average allowable bearing strength of the drill pile is 70.25 tons (51%). The re-analysis of the load combination resulted in additional spun piles at 44 points. In the damaged bored pile concrete, namely by adding cast to the outer layer (concrete-jacketing) to cover the exposed reinforcement layer, and adding separate reinforcement on the inside of the concrete to anticipate if the outer reinforcement is damaged due to corrosion.Fondasi harus dibangun di atas tanah keras agar bangunan tetap stabil dan kokoh. Memastikan kekuatan fondasi adalah upaya dini untuk mencegah sudden collapse pada bangunan di kemudian hari. Penelitian ini dilakukan untuk mengetahui kuat dukung tanah pada ujung tiang fondasi dan mengamati sejauh apa kerusakan beton tiang bor pada bangunan yang baru masih dalam tahap pembangunan fondasi. Data penelitian diperoleh dari hasil pengujian PDA (Pile Driving Analyzer) dan PIT (Pile Integrity Test) pada fondasi bangunan jenis bored pile D80. Pada gedung yang berdekatan, yang dikerjakan dengan sistem yang sama dan menggunakan spun pile D50. Data kuat dukung ultimate hasil manometer alat uji hidraulik 175 ton untuk pile D50. Dari analisis uji PDA, diperoleh nilai kuat dukung ijin rata-rata tiang bor adalah 70,25 ton (51%). Analisis ulang terhadap kombinasi beban menghasilkan tambahan spun pile di 44 titik. Pada beton bored pile yang mengalami kerusakan, dilakukan perbaikan seperti penambahan cor pada lapisan luar (concrete-jacketing) untuk menutupi lapisan tulangan yang terekspos, dan penambahan tulangan terpisah di sisi dalam beton untuk antisipasi bila tulangan luar rusak akibat korosi.

Load combination analysis by ‘Directional simulation in the load space’

2006 ◽  
Vol 21 (2) ◽  
pp. 159-170 ◽  
Author(s):  
William A. Gray ◽  
Robert E. Melchers
Keyword(s):  
Load Combination

A Load Combination Method for Aseismic Design of Multiple Supported Piping Systems

1989 ◽  
Vol 111 (1) ◽  
pp. 10-16 ◽  
Author(s):  
K. Suzuki ◽  
A. Sone
Keyword(s):  
Structural Model ◽  
Response Spectrum ◽  
Reduction Factor ◽  
Combination Method ◽  
Piping System ◽  
Response Reduction Factor ◽  
Load Combination ◽  
Combination Scheme ◽  
Piping Systems ◽  
Reduction Effect

A new load combination scheme for seismic response calculation of piping systems subjected to multiple support excitations is presented. This scheme has an advantage, such that the cross-correlation among support excitations are properly taken into account by use of a stationary random vibration approach. The authors also present the idea of generating a “multi-excitation floor response spectrum.” First, using a simple analytical SDOF piping system to two support excitations and a simple Z-shaped piping model for shaking test, the combination law is supplied to various correlation cases of two support excitations and the maximum responses of piping in a fundamental mode is calculated. Second, nonlinear characteristics such as gap and friction appearing between piping itself and supports are specifically investigated. The response effect due to these nonlinearities is evaluated by the results through the shaking test with a piping-support structural model, and the amount of response reduction effect is represented by “a response reduction factor β.”

Comparative Study on Design of Exposed Penstock Laid on Ground Using Chinese and American Specifications

2014 ◽  
Vol 580-583 ◽  
pp. 2000-2006
Author(s):  
Lei Hu ◽  
He Gao Wu ◽  
Chang Zheng Shi ◽  
Ying Han Xie
Keyword(s):  
Comparative Study ◽  
Wall Thickness ◽  
Structural Design ◽  
Shell Thickness ◽  
Pressure Vessels ◽  
Hydropower Station ◽  
Allowable Stress ◽  
Direct Factor ◽  
Safety Coefficient ◽  
Load Combination

In this paper, differences by using selected three typical specifications—DL/T 5141-2001 (Chinese), ASCE No.79 in the version of 1993(American) and ASCE No.79 in the version of 2012 (American)—in structural design of exposed steel penstock were explored. A practical example about exposed penstock laid on ground applied in hydropower station was also used to analyze specifications clearly. The result shows that the main differences between Chinese and American specifications are allowable stress and load combination. The former is direct factor of calculating exposed penstock shell thickness. Therefore, ASCE No.79 (2012) designs the minimum wall thickness, followed by DL/T 5141-2001 and the last is ASCE No.79 (1993), which is correspondingly contrary to sort by allowable stress. Basically, ASCE No.79 (2012) defines lower safety coefficient for exposed penstock, which is identical with authoritative rules of pressure vessels in the U.S.A and EU. The safety of DL/T 5141-2001 has been proved via rich engineering experience and this specification is recommended for Chinese projects. Besides, ASCE No.79 (2012) is recommended.

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