scholarly journals TINJAUAN FATIK ELEMEN STRUKTUR ATAS JEMBATAN TERHADAP LHR DAN USIA RENCANA SESUAI AASHTO 2012

2019 ◽  
Vol 1 (3) ◽  
pp. 247-254
Author(s):  
Fauzri Fahimuddin ◽  
Dio Akbar Hakim ◽  
Andi Indiandto
Keyword(s):  
Fatigue Analysis ◽  
Dynamic Loads ◽  
Stress Range ◽  
Dead Load ◽  
Truck Traffic ◽  
Maintenance And Repair ◽  
Old Left ◽  
Bridge Collapse ◽  
One Step ◽  
Truss Bridge

AbstractA lot of structures failure on the bridge, causes a collapsed to the bridges. The reason of the collapsed was dynamic loads that happen on the bridge. Dynamic loads make stress and relax happen at the same time. Fatigue analysis is an analysis that calculate the dynamic load that happen on the bridge, with counting the big vehicle or truck. Fatigue analysis can’t analyze all the element with one step. In this research the bridge was a truss bridge with span 70 m as the main structure. In fatigue analysis, stress that used was stress that caused by dead load and stress that caused by the big vehicle or truck passing through. The value between that stresses used to call stress range. In AASHTO the value of truck that passing truck in a traffic called Average Daily Truck Traffic (ADTT). Stringer, cross beam, and main truss was the element that will be analyzed. In this structure we use category B, where ADTT is 860, Threshold is 110 MPa, A is 39,3 x 1011, and the n is 1. From stress range that happen in the structure, we can find the age and ADTT until the bridge collapse because fatigue. In the end the elements that had the lowest age and the lowest ADTT was the main truss, where it just has 27 years old left and can only take 299 truck/day. Then the bridge has to get a maintenance and repair before it gets 27 years old.Keywords : Fatigue, age, ADTT, stress rangeAbstrakBanyak terjadinya kegagalan struktur pada jembatan, yang menyebabkan keruntuhan pada jembatan. Hal itu disebabkan oleh beban dinamis yang terjadi pada jembatan. Beban dinamis membuat terjadinya tegangan dan relaksasi dalam waktu bersamaan. Analisa fatik merupakan perhitungan dengan memperhitungkan beban dinamis yang terjadi pada jembatan, dengan beban dianggap sebagai kendaraan besar atau truk. Memperhitungkan kondisi fatik tidak dapat dihitung langsung untuk satu jembatan. Dalam analisa ini menggunakan jembatan dengan bentang 70 m sebagai struktur rangka atasnya. Pada Analisa fatik tegangan yang dihitung berupa tegangan akibat beban sendiri pada jembatan dan tegangan ketika dilalui oleh kendaraan besar atau truk. Perbedaan tegangan tersebut biasa disebut dengan stress range. Pada AASHTO, lalu lintas harian rata-rata (LHR) biasa disebut Average daily truck traffic (ADTT). Elemen yang dihitung berupa stringer, cross beam, dan batang rangka utama. Pada struktur ini kategori yang digunakan adalah kategori B dengan ADTT sebesar 860, threshold sebesar 110 MPa, A sebesar 39,3 x 1011 MPa3 dan n sebesar 1. Dari stress range yang didapat, maka dapat dicari umur jembatan serta ADTT hingga jembatan pada kondisi fatik. Dapat disimpulkan bahwa elemen yang mempunyai umur dan ADTT terendah adalah batang rangka utama, dengan nilai umur rencana 27 tahun dan ADTT 299 truk/hari. Dengan demikian dapat dinyatakan bahwa jembatan harus diberi perkuatan saat umur mendekati 27 tahun.Kata kunci : Fatik, umur rencana, ADTT, stress range.

Dead Load Evaluation through Truss Bridge Deconstruction Monitoring

2018 ◽  
Vol 23 (1) ◽  
pp. 04017115
Author(s):  
Brittany Murphy ◽  
James Locum ◽  
Michael Belser ◽  
Kassam Bhegani ◽  
Matthew Yarnold
Keyword(s):  
Dead Load ◽  
Truss Bridge ◽  
Load Evaluation

On the Evaluation of the Stress State in Rail Head for Assessing Fatigue Resistance

2014 ◽  
Vol 891-892 ◽  
pp. 1157-1162 ◽  
Author(s):  
Chung Lun Pun ◽  
Qian Hua Kan ◽  
Peter J. Mutton ◽  
Guo Zheng Kang ◽  
Wen Yi Yan
Keyword(s):  
Stress State ◽  
Fatigue Resistance ◽  
Fatigue Analysis ◽  
Multiaxial Fatigue ◽  
Rolling Contact ◽  
Single Parameter ◽  
Von Mises Stress ◽  
Stress Range ◽  
Rail Head ◽  
Von Mises

To search for a single parameter to evaluate the stress state in rail head during wheel/rail rolling contact situations, the stress-based and the strain based phenomenological approaches for multiaxial fatigue analysis can be considered as the candidates. Following the stress-based approach, the maximum von Mises stress range can be applied as a single parameter to evaluate the stress state in the rail head. However, the von Mises stress range only relies on the stress field in the rail head for the fatigue analysis, which is not sufficient for assessing the fatigue resistance of the rail steel. The Smith-Watson-Topper (SWT) method, the strain-based phenomenological approach for multiaxial fatigue analysis which considers stress, elastic strain and plastic strain components, is then adopted to study rolling contact fatigue in the rail head. Combining with the three-dimensional finite element modelling of a steady-state wheel/rail rolling contact, the numerical procedure to calculate the SWT parameter in the rail head is presented. The capability of the SWT method to predict the initiation of fatigue cracks in the rail head is confirmed in a case study. Consequently, the maximum SWT parameter is proposed as a single parameter to effectively evaluate the stress state in the rail head.

scholarly journals Effect on high rise structure expose to blast load

2020 ◽  
pp. 350-355
Keyword(s):  
Design Process ◽  
Wind Load ◽  
Dynamic Loads ◽  
Blast Load ◽  
Charge Weight ◽  
Live Load ◽  
Dead Load ◽  
High Rise ◽  
Lateral Forces ◽  
The Impact

The impression of blast load on building is very important things to consider in a design process. A bomb detonation within structures or straightaway the building can drive damage on the building either in external or internal structural frames, by collapse of walls etc. These kinds of affliction are uncommon and man-made disasters. The impact of blast load is equivalent to a dynamic loads and that demand to take caution while calculating of it. Someone can calculate as other lateral forces like earthquake and wind load. Design fully blast resistant structures is not pragmatic and economic, till the knowledge of mitigating its effect while designing new structures or maintaining old one with its less impact is identical. In this present study, the behavior of G+15 storey RCC structure is analyzed under the blast load with the help of ETAB software. According to the IS code provision, the dead load, live load and wind load has been considered to study the effect of it. Also, the distance of blast and its charge weight is very according to IS 4991-1968.

SERB Devices for the Isolation of Buildings and Equipment Against Shocks, Vibrations and Seismic Movements

2008 ◽  
Author(s):  
Viorel Serban ◽  
Adrian Panait ◽  
Marian Androne
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Horizontal Plane ◽  
Nuclear Power ◽  
Dynamic Loads ◽  
Static Loads ◽  
Maintenance And Repair ◽  
Compression Load ◽  
Aging Phenomenon ◽  
Very High

The paper presents new types of devices to isolate buildings and equipment against shocks, vibrations and seismic movements, developed by SITON in cooperation with other units in Romania. The new devices, called SERB devices, can overtake very large static loads (over 3000KN) over which dynamic loads are overlapping and damped. The devices allow the “cutting-off” of the dynamic action coming from the environment to the isolated component (building or equipment) and the shocks and vibrations generated by the component to the environment. The relative displacements allowed by the devices in horizontal plane, reach up to ±200mm and their capacity to dissipate the energy is very high. The devices can overtake compression and tension loads up to half of the maximum compression load. The devices are made of materials that practically, are not affected by the aging phenomenon and they may be guaranteed for the entire service-life of a nuclear power plant, without maintenance and repair. The sizes of the devices are small if compared with the sizes of the existing devices and the performances are similar. The radiation resistance capacity is very good allowing thus their use in all the areas of a nuclear-power plant.

scholarly journals Fatigue Analysis of Dozer Push Arms under Tilt Bulldozing Conditions

Machines ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 38
Author(s):  
Longye Pan ◽  
Xianglong Guan ◽  
Xingwei Luan ◽  
Yajun Huang ◽  
Ruwei Zhang ◽  
...  
Keyword(s):  
Experimental Tests ◽  
Fatigue Analysis ◽  
Virtual Simulation ◽  
The Other ◽  
Dynamic Loads ◽  
Virtual Model ◽  
Loading History ◽  
Time Histories ◽  
The Right ◽  
Unbalanced Loads

Tilt bulldozing generates unbalanced loads on two push arms, which leads to the service lives of the two push arms being different. Because the push arms rotate in triaxial directions during tilt bulldozing, it is difficult to accurately analyze the fatigue life of the push arm with one specific boundary condition and loading history. Therefore, a fatigue analysis of the push arms under tilt bulldozing conditions is proposed based on co-simulation of RecurDyn-EDEM-AMESim in this paper. The control of tilt bulldozing conditions is realized automatically according to the tilt angle and blade depth. The dynamic loads of the push arms are accurately calculated in this virtual model. Subsequently, the stress–time histories are obtained to investigate the fatigue lives of push arms. Both the overall damage and the initiation positions of the cracks are predicted herein. It is determined that the fatigue lives of the right and left push arms are 7,317.84 h and 39,381.89 h, respectively. Thus, the life of the push arm on the blade’s tilted side is reduced by 81.42% compared to the other side. Additionally, experimental tests are conducted to verify the accuracy of the virtual model. Analysis results indicate that the strains of the push arms according to the virtual simulation are close to those measured in the experiments.

Critical Plane Search Method for Biaxial and Multiaxial Fatigue Analysis

2016 ◽  
Author(s):  
Kumarswamy Karpanan
Keyword(s):  
Shear Stress ◽  
Stress State ◽  
Strain Amplitude ◽  
Stress Amplitude ◽  
Maximum Shear Stress ◽  
Fatigue Analysis ◽  
Search Method ◽  
Stress Range ◽  
Critical Plane ◽  
Stress Strain

For complex cyclic loadings, stress- or strain-based critical plane search methods are commonly used for fatigue analysis of the structural components. Complex loadings can result in a non-proportional type loading in which it is difficult or impossible to determine the plane with maximum shear stress/strain amplitude. ASME Sec VIII, Div-3 fatigue analysis for non-welded components is a shear stress based fatigue analysis method and, for non-proportional loading, uses the critical plane search method to calculate the plane with maximum shear stress amplitude. For a two-dimensional non-proportional stress state, analytical stress transformation equations can be used to calculate the shear stress or strain amplitude on any plane at a point. The shear stress range on each plane is the difference between the maximum and minimum shear stress. For a three-dimensional stress state, shear stress amplitude calculations are much more complicated because the shear stress is a vector and both magnitude and direction change during the loading cycle. In ASME VIII-3, the maximum shear stress range among all planes, along with the normal stress on the plane, is used to calculate the stress amplitude. This paper presents a method to calculate the shear stress/strain amplitude using 3D transformation equations. This method can be used for any stress- or strain-based critical plane search method. This paper also discusses ASME proportional and non-proportional fatigue analysis methods in detail.

A Proposal to Consider Cycle Counting Methods for Fatigue Analysis of Nuclear and Conventional Power Plant Components

2016 ◽  
Author(s):  
Felippe M. S. Costa ◽  
José Luiz F. Freire ◽  
Jürgen Rudolph ◽  
José Eduardo Maneschy
Keyword(s):  
Finite Element ◽  
Analytical Solution ◽  
Time History ◽  
Peak Stress ◽  
Fatigue Analysis ◽  
Transient Temperature ◽  
Stress Range ◽  
Structural Components ◽  
Finite Element Software ◽  
Asme Code

This paper points out some relevant aspects of the simplified elasto-plastic fatigue analysis as addressed in the ASME Code Section III Subsection NB and its application to two structural components that are subjected to a slow or to a fast thermal transient. The structural components considered are a thick-walled pipe and a nozzle-to-vessel junction. For the case of the thick-walled pipe, a closed form analytical solution proposed by Albrecht for pipes subjected transient temperature loading was implemented and its results were compared to coupled thermal and mechanical finite element analyses using a commercial finite element software. The application of the analytical solution allows for an optimization of the time consumed to obtain the stresses that occur across the thickness of the pipe as a function of time, i.e. the membrane plus bending plus peak stress range, Sp. The analytical solution equally allows for the linearization of the stress components actuating along the pipe thickness for all time steps considered within the thermal stress solution. This yields the membrane plus bending stress range, Sn, and allows for a design code conforming plasticity correction by means of Ke factors. In the considered case of the nozzle-to-vessel junction, a finite element solution was used. It was one aim of the study to point out, that under fast transients loading situations the relevant stresses Sp and Sn do not necessarily coincide with each other. In the ASME Code the alternating stress Sa is a function of the factor Ke and of the range of Sp, with Ke being a function of the range of Sn and of the material properties. Consequently, a non-conservative fatigue analysis may result in the case of performing cycle counting only based on the time history of the critical Sp values and simply assigning the corresponding Sn and Ke values. This paper exemplifies one of those cases and proposes a method to overcome this problem.

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