Buckling Strength and Parameter Analysis on Stiffened Flange Plate under Compression

2013 ◽  
Vol 838-841 ◽  
pp. 1159-1164
Author(s):  
Wen Ru Lu ◽  
Jin Di

The buckling strength of stiffened flange plate under compression was researched by referring to BS5400, Japanese Specification for Highway Bridges and Eurocode in order to research calculation methods of stiffened flange plate under compression in foreign design codes of steel bridge which were based on different design theories. Test results of ultimate bearing capacity of stiffened flange plate under compression were compared with calculation results according to those codes. The effects of constructive parameters such as the thickness of flange plate, width of subpanel, thickness of plate and width of inclined web plate in rib on buckling strength of stiffened flange plate under compression were researched respectively. The results showed, when increasing the thickness of flange or decreasing the width of plate divided by rib's web, calculation results of buckling strength increased at first and then leveled off according to Japanese Specification for Highway Bridges. However the buckling strength declined slowly according to BS5400 and Eurocode. When increasing the thickness of plate or decreasing the width of inclined web plate of rib, calculation results increased at the beginning and leveled out then. If ribs satisfy the rigidity demands, calculation results of buckling strength would remain the same as the sizes of rib were changed according to Japanese Specification for Highway Bridges.

2021 ◽  
pp. 875529302098801
Author(s):  
José Wilches ◽  
Hernán Santa Maria ◽  
Roberto Leon ◽  
Rafael Riddell ◽  
Matías Hube ◽  
...  

Chile, as a country with a long history of strong seismicity, has a record of both a constant upgrading of its seismic design codes and structural systems, particularly for bridges, as a result of major earthquakes. Recent earthquakes in Chile have produced extensive damage to highway bridges, such as deck collapses, large transverse residual displacements, yielding and failure of shear keys, and unseating of the main girders, demonstrating that bridges are highly vulnerable structures. Much of this damage can be attributed to construction problems and poor detailing guidelines in design codes. After the 2010 Maule earthquake, new structural design criteria were incorporated for the seismic design of bridges in Chile. The most significant change was that a site coefficient was included for the estimation of the seismic design forces in the shear keys, seismic bars, and diaphragms. This article first traces the historical development of earthquakes and construction systems in Chile to provide a context for the evolution of Chilean seismic codes. It then describes the seismic performance of highway bridges during the 2010 Maule earthquake, including the description of the main failure modes observed in bridges. Finally, this article provides a comparison of the Chilean bridge seismic code against the Japanese and United States codes, considering that these codes have a great influence on the seismic codes for Chilean bridges. The article demonstrates that bridge design and construction practices in Chile have evolved substantially in their requirements for the analysis and design of structural elements, such as in the definition of the seismic hazard to be considered, tending toward more conservative approaches in an effort to improve structural performance and reliability for Chilean bridges.


Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3955
Author(s):  
Yonghan Ahn ◽  
Hanbyeol Jang ◽  
Junghyon Mun

The purpose of this study is to compare the load calculation results by a model using the air changes per hour (ACH) method and a model using an airflow network (AFN) and to ascertain what causes the difference between the two models. In the basic case study, the difference in the heat transfer distribution of the model in the interior space was investigated. The most significant difference between the two models is the heat transfer that results from infiltration. Parameter analysis was performed to investigate the relationship between the difference and the environmental variables. The result shows that the greater the difference is between the air temperature inside the balcony and the outdoor air temperature, and the greater the air flows from the balcony to the residential area, and the greater the heating and cooling load difference occurs. The analysis using the actual weather files of five domestic cities in South Korea rather than a virtual case shows that the differences are not so obvious when the wind blows at a constant speed throughout the year, but are dominant when the wind does not blow during the night and is stronger alongside the occurrence of sunlight during the day.


Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2978
Author(s):  
Zhi-Min Liu ◽  
Xue-Jin Huo ◽  
Guang-Ming Wang ◽  
Wen-Yu Ji

Compared with straight steel–concrete composite beams, curved composite beams exhibit more complicated mechanical behaviors under combined bending and torsion coupling. There are much fewer experimental studies on curved composite beams than those of straight composite beams. This study aimed to investigate the combined bending and torsion behavior of curved composite beams. This paper presents static loading tests of the full elastoplastic process of three curved composite box beams with various central angles and shear connection degrees. The test results showed that the specimens exhibited notable bending and torsion coupling force characteristics under static loading. The curvature and interface shear connection degree significantly affected the force behavior of the curved composite box beams. The specimens with weak shear connection degrees showed obvious interfacial longitudinal slip and transverse slip. Constraint distortion and torsion behavior caused the strain of the inner side of the structure to be higher than the strain of the outer side. The strain of the steel beam webs was approximately linear. In addition, fine finite element models of three curved composite box beams were established. The correctness and applicability of the finite element models were verified by comparing the test results and numerical calculation results for the load–displacement curve, load–rotational angle curve, load–interface slip curve, and cross-sectional strain distribution. Finite element modeling can be used as a reliable numerical tool for the large-scale parameter analysis of the elastic–plastic mechanical behavior of curved composite box beams.


2015 ◽  
Vol 1096 ◽  
pp. 562-566 ◽  
Author(s):  
Bo Yu ◽  
Tao Hong ◽  
Jian Zhang ◽  
Qing Yu Liang

Due to the superior structure style, orthotropic steel bridge deck has been getting more and more widely practical application. The static and fatigue tests of the orthotropic steel bridge deck models were carried out in this research paper, which presented the fatigue damage developing laws, compared the test results with homogeneous test results in existing documents, and according to the relative fatigue accumulative damage theory, the fatigue accumulative damage equations of the sectional specimen and the whole specimen are respectively studied.


Author(s):  
James M. Fragomeni ◽  
Giridhar Venugopal

Many systems that work on the processing of energy can be modeled in terms of that energy. The energy that is given to the system may be stored or dissipated in the form of heat. It was proposed to extend this concept to attainment of critical level of stored energy and/or dissipated energy for occurrence of buckling of a metal column under compressive loading. The fact that Energy Factor Parameter (E.F.P.) computed from the experimental true stress-true strain values, suddenly decreased and approached value close to zero indicated either buckling and/or softening, but deviated with the E.F.P. computed from the theoretical true stress and true strain values. The 7050-T7451 (Al-Zn-Mg-Cu-Zr) and Al-Li-Cu aluminum alloys in longitudinal and transverse grain orientations were compression tested for mechanical properties of yield strength, buckling strength, strength coefficient, strain hardening exponent. Correlation between ratio of buckling strength and yield strength with aging time for preaged ASTM compression specimens was established. The compression deformation of aluminum alloy 7050 was modeled using finite element analysis, with the experimental testing parameters and the database in the software package.


2020 ◽  
Vol 57 (5) ◽  
pp. 742-753
Author(s):  
Ignatius Tommy Pratama ◽  
Chang-Yu Ou ◽  
Jianye Ching

This study calibrated the required factors of safety of five analysis methods for sand boiling using reliability theory. The factors of safety computed by the five analysis methods were compared with the results of a series of sand boiling model tests. The comparison shows that rigorous methods (Terzaghi’s and Harza’s methods) were more accurate in predicting the factors of safety compared to the simplified methods (Harr’s, simplified Terzaghi’s, and simplified Harza’s methods). The statistics of the model factor for each method, defined as the actual factor of safety divided by the computed one, was calibrated by the model test results. These statistics were then used to establish the relationship between the target probability of failure and the required factor of safety by reliability theory. Verification using a full-scale sand boiling case history shows that the required factor of safety calibrated by the reliability theory was more reasonable than the required factors of safety in references and design codes.


2018 ◽  
Vol 5 (2) ◽  
pp. 270-278 ◽  
Author(s):  
M. Basyir ◽  
M. Nasir ◽  
Suryati Suryati ◽  
Widdha Mellyssa

Emergency Reporting Application is an android-based application that serves to help the community in reporting the emergency condition. This application allows users to choose and contact the emergency services office, without the need to notice their position and phone number. Selection of emergency services office is also automatically selected by the system by taking into account the distance between the complainant and the emergency services office. The selected emergency services office is the nearest emergency service office from the complainant so that the delay in coming assistance can be minimized. Therefore, this proposed application requires a GPS feature to recording, reporting and SMS positioning for message delivery of reports. The distance between the position of the complainant and the position of the emergency service office, in the form of latitude and longitude data, is requested using the Haversine formula taking into account the degree of curvature of the earth. Emergency service offices include police and hospital offices spread over 25 different districts. Furthermore, the reporter's position calculation results were compared with all selected emergency service offices and obtained 1 nearest emergency service office. Calculating the accuracy and delay value of the system will do system testing. Accuracy test results using the method of 100% Haversine and the average delay of the system is 4.5 seconds.


Author(s):  
Wadie Kidess

In order to get the authorization for issuing energy performance certificates in Slovenia, the expert candidate has to attend the prescribed course and pass the exam. The simplified method for heat losses calculation that is taught at this course neglects the thermal bridges, raising concerns whether the calculation results are reliable. In this paper we have compared three methods for calculation of thermal losses for a “typical” family house. The first is the above mentioned simplified calculation using a correctional factor; the second takes into account the thermal bridges, using linear thermal transmittances obtained by numerical calculation, and the third takes into account the thermal bridges, using default values for linear thermal transmittances. Noting that the second method returns the most exact values, we have found that the first method results are too large, yet still smaller than the third method results.


POROS ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. 121
Author(s):  
Muhammad Ridwan Ridwan ◽  
Noviyanti Nugraha Nugraha

Biomass power plants are electricity generators with alternative energy that utilize organicmaterials, in this case cow dung. The cow dung is then processed to produce syngas. Syngas is used as fuelto turn turbines. In previous studies, a cow manure gasification reactor was designed and manufactured.This reactor is part of a biomass power plant system (PLTBm) which is made separately. The power outputtarget of this PLTBm is 370 kW. The purpose of this study was to examine the performance of the downdraftreactor of cow dung biomass, namely discharge, temperature, and analyze the gas content released by thereactor so that the power that can be generated by the reactor can be obtained. The test results obtained acombustion chamber temperature of 580°C and a discharge of 0.285 m3/s. The composition of the outputgas is acetylene 58.16%, hexane 27.66%, butane 6.38%, and methane 7.8%. From the calculation results,the power generated by the reactor is 342 kW.


2019 ◽  
Vol 4 (1) ◽  
pp. 63
Author(s):  
Akhmad Nasir

This study aims to find out and analyze the influence of eWOM (Electronic Word Of Mouth) Trust and Purchase Intention on Students in the English village of Pare-Kediri. The population in this study were those who took courses at the Pare-Kediri English village course institute in January-March 2019 which obtained a sample of 100 respondents with accidental sampling technique. Methods of collecting data using questionnaires, observation, interviews, and library studies. The test results partially show that there is a significant and significant effect on the trust variable on Purchase Intention as evidenced by a significant value of 0,000 which is smaller than 0.05 (0,000 <0,05). The partial test results show that there is a significant and significant effect between eWOM variables on Purchase Intention as evidenced by a significant value of 0.005 which is smaller than 0.05 (0.005 <0.05). Based on the calculation results obtained a significant value is 0,000. This shows that the significant value of the test is the trust variable F and eWOM <0.05, which means that the results of this simultaneous test are trust and eWOM has an effect on Purchase Intention. Penelitian ini bertujuan untuk mengetahui dan menganalisis pengaruh Kepercayaan Dan eWOM ( Elektronik Word Of Mouth ) teradap Purchase Intention pada Pelajar di kampung inggris Pare-Kediri. Populasi dalam penelitian ini adalah yang mengambil kursus di lembaga kursus kampung inggris Pare-Kediri pada bulan Januari-Maret 2019 yang  diperoleh sampel sebanyak 96 responden dengan teknik accidental sampling. Metode pengumpulan data menggunakan kuesioner, obsevasi, wawancara, dan Studi kepustakaan. Hasil pengujian secara parsial menunjukan bahwa berpengaruh dan signifikan antara variabel kepercayaan terhadap Purchase Intention yang dibuktikan dengan nilai signifikan sebesar 0,000 dimana lebih kecil dari 0,05 (0,000 < 0,05). Hasil pengujian secara parsial menunjukan bahwa berpengaruh dan signifikan antara variabel eWOM terhadap Purchase Intention yang dibuktikan dengan nilai signifikan sebesar 0,005 dimana lebih kecil dari 0,05 (0,005 < 0,05). Berdasarkan hasil perhitungan diperoleh nilai signifikan adalah 0,000. Hal ini menunjukan bahwa nilai signifikan uji F variabel kepercayaan dan eWOM <0,05 yang berarti hasil dari pengujian simultan ini adalah kepercayaan dan eWOM berpengaruh terhadap Purchase Intention.


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