scholarly journals EVALUASI PENYEBAB KEGAGALAN DAN PERBAIKAN STRUKTUR JEMBATAN RANGKA BAJA DENGAN BENTANG 54 m = EVALUATION OF THE CAUSES OF FAILURE AND REPAIR OF 54 M SPAN TRUSS BRIDGE STRUCTURE

2019 ◽  
Vol 13 (1) ◽  
pp. 17
Author(s):  
Tri Handayani
Keyword(s):  
Structural Members ◽  
Design Strength ◽  
Repair Method ◽  
Steel Material ◽  
Bridge Evaluation ◽  
Bolt Holes ◽  
Bridge Failure ◽  
Truss Bridge ◽  
Safe Condition

In this paper the evaluation and repair of a bridge failure are presented. The method is of analytical bridge evaluation, which consists of in-situ visual inspection, measurement of the bridge dimensions and quality test of the steel material. The data were used as input in structure modeling using SAP 2000 in order to calculate the required strength (Ru) of each structural members. Calculation were done to obtain the design strength (ØRn) of structural members and connections.The bridge components are in a safe condition if its design strength is greater than or equal to the required strength or ØRn ≥ Ru, If not, the bridge is categorized as failed and then a repair method and strengthening shall be be performed. The result showed that all of structural members and connections are in a safe condition. Bridge failure is caused by such factors as less precise execution in the field, combination of a large bolt holes and tightening bolts that have not reached the minimum tensile strength.The proposed bridge repair method is to provide two pieces of plates. The plates were welded at the end of the rod and drilled at the position of the existing bolt holes in order to avoid the bolt shifting.Keywords : bridge failure, bridge evaluation, required strength, design strength, , repaired method  AbstrakPada makalah ini disajikan evaluasi dan perbaikan dari kasus kegagalan sebuah jembatan. Metode yang digunakan adalah evaluasi jembatan secara analitis yang terdiri dari pemeriksaan secara visual di lapangan, pengukuran dimensi jembatan dan pengujian mutu bahan baja. Data tersebut sebagai input dalam pemodelan struktur dengan SAP 2000 dan diperoleh kuat perlu (Ru) masing-masing batang. Perhitungan juga dilakukan terhadap kuat rencana (ØRn) baik batang maupun sambungan. Komponen jembatan dikatakan aman jika kuat rencana lebih besar atau sama dengan kuat perlu atau ØRn ≥ Ru. Kemudian dilakukan penentuan kegagalan jembatan serta metode perbaikannya. Hasil penelitian menunjukkan bahwa semua batang dan sambungan aman sehingga penyebab kegagalan jembatan bukan karena kekuatan batang maupun sambungannya melainkan faktor pelaksanaan di lapangan yang tidak tepat yaitu kombinasi antara adanya lubang baut yang besar dan pengencangan baut yang belum mencapai gaya tarik minimumnya. Metode perbaikan jembatan yang diusulkan adalah dengan memberi dua buah pelat penguat yang dilas pada ujung batang dan dilubangi sesuai dengan posisi lubang baut yang ada agar tidak terjadi pergeseran baut.Kata kunci : kegagalan jembatan, evaluasi jembatan, kuat perlu, kuat rencana, , metode perbaikan

Influence of Spatial Variability of Seismic Shock on Steel Hall with Experimentally Determined Elasto-Plastic Parameters of Steel Material

2015 ◽  
Vol 744-746 ◽  
pp. 884-889
Author(s):  
Dorota Jasinska ◽  
Joanna M. Dulinska ◽  
Pawel Boron
Keyword(s):  
Spatial Variability ◽  
Seismic Excitation ◽  
Plastic Behavior ◽  
Structural Members ◽  
Steel Material ◽  
Dynamic Analyses ◽  
Seismic Shock ◽  
Wave Passage ◽  
Delay Dependent ◽  
Excitation Model

In the paper the influence of spatial variability of a seismic shock on an industrial steel hall was examined. Different models of seismic excitation were introduced. Firstly, a uniform seismic excitation model was applied, assuming identical motion of all supports of the hall. Then, a non-uniform excitation model was implemented. In that model subsequent points of the ground in the direction of wave propagation repeat the same motion with a certain time delay dependent on the wave velocity. Two direction of the wave passage were assumed: longitudinal (along the longer side of the hall) and transverse (along the shorter side of the hall). To guarantee proper nonlinear elasto-plastic behavior of the structure, the material parameters of the steel were determined experimentally. The dynamic analyses revealed that the response of the hall to the seismic shock was reported beyond the elastic range. Plastic effects appeared in some zones of the primary as well as the secondary structural members of the object, regardless of the excitation model. The model of non-uniform seismic excitation with transverse wave passage turned out to have the greatest impact on the dynamic response of the hall; the plastic strains obtained for that model were much greater than those obtained for other models. The transverse non-uniform excitation generated irreversible strains almost 3 times greater than the uniform excitation. The evolution of significant plastic effects was observed mainly for non-uniform excitations in the lower parts (girts and columns) of the hall, which were strongly affected by the different motions of the ground.

AN INVESTIGATION OF EIGENVALUES OF SHEET METAL UNDERGOING BENDING STRESSES

2015 ◽  
Vol 76 (8) ◽  
Author(s):  
Wan Sulaiman Wan Mohamad ◽  
Ahmad Azlan Mat Isa ◽  
Ahmad Syahmi Abu Talib
Keyword(s):  
Natural Frequencies ◽  
Dynamic Properties ◽  
Modal Parameters ◽  
Structural Members ◽  
Sheet Metals ◽  
Ansys Software ◽  
Bending Stresses ◽  
Different Shapes ◽  
Bent Plates

Accurate prediction of dynamic properties of system is important to ensure the dynamic based design integrity of its member is not compromise. It will reduce or possibly eliminate the possibilities of further modifications in-situ of real system. On this account, this study investigates the modal parameters of the pre-stress sheet metals undergoing bending stresses which is commonly used in practice as structural members. In addressing this issue, three different shapes of sheet metals of similar thickness were studied i.e. straight plate, U-shaped and V-shaped plates. The natural frequencies of these configurations were determined experimentally using the Operational Modal Analysis (OMA). Numerical values were obtained using ANSYS software. Results of these shapes acquired experimentally and numerically were then compared and analyzed. Significant reduction in the eigenvalues of is observed on bent plates both experimentally and numerically as compared to flat plate.

Strength Analysis of Bulk Cement Truck Body Based on NASTRAN

2014 ◽  
Vol 678 ◽  
pp. 572-575
Author(s):  
Qian Jia
Keyword(s):  
Optimization Design ◽  
Rapid Development ◽  
Strength Analysis ◽  
Development Research ◽  
Analysis Software ◽  
Element Analysis ◽  
Design Strength ◽  
Steel Material ◽  
Economic Construction

With the rapid development of our nation’s economic construction, bulk cement trucks have developed rapidly among the special vehicles. The entity model of the bulk cement body tank was created using 3D drawing software UG. The model’s accuracy was proved through calculation and on the basis of the entity model the strength of structure was analyzed by Finite Element Analysis software Nastran. Lightweight processing of steel material was made to reduce the overall quality of cement truck and the loading capacity was increased under the condition of meeting the design strength. The theory basis on the development research and optimization design of bulk cement truck tank has been provided.

Corrosion Behavior of Carbon Steel and Stainless Steel Materials under Salt Deposits in Simulated Dry Repository Environments

2002 ◽  
Vol 757 ◽  
Author(s):  
Lietai Yang ◽  
Roberto T. Pabalan ◽  
Lauren Browning ◽  
Darrell S. Dunn
Keyword(s):  
Stainless Steel ◽  
Carbon Steel ◽  
Relative Humidity ◽  
Multielectrode Array ◽  
Chloride Salt ◽  
Uniform Corrosion ◽  
Salt Deposit ◽  
Steel Material ◽  
Deliquescence Relative Humidity

ABSTRACTIn-situ coupled multielectrode array sensors were used to measure the non-uniform corrosion of carbon steel and stainless steel materials under KCl salt deposit in simulated dry repository environments. It was found that the initiation of non-uniform corrosion occurs at a relative humidity that is 14% lower than the deliquescence relative humidity of the chloride salt. It was found also that once significant corrosion had occurred, the non-uniform corrosion process for the carbon steel material under the salt deposit continues at relative humidities as low as 27%.

scholarly journals Global-local modeling of single-shear composite – metal and composite – composite bolt joints in aircraft structural components

2020 ◽  
Author(s):  
V.P. Eremin ◽  
A.A. Bolshikh
Keyword(s):  
Prediction Models ◽  
The Body ◽  
Strength Analysis ◽  
Structural Members ◽  
Structural Components ◽  
Mechanical Contact ◽  
Design Strength ◽  
Composite Joint ◽  
Local Modeling ◽  
Local Strength

In performing design strength analysis of connection areas of composite — metal and composite — composite types of structural load-bearing wing and empennage elements of the aircraft implemented using mechanical fasteners, it is necessary to considerthe factors determining the local strength of these areas: the conditions of mechanical contact of the body, bolt head and cap with connected elements, the connected elements contact with each other and the effects of friction. These factors can be taken into account only by applying the global-local modeling approach for constructing 3D prediction models of composite — metal and composite — composite joint zones of aircraft caisson structural members. To solve this problem, a method is proposed defining the means and tools of modeling, algorithms for constructing a prediction model and performing calculations, as well as procedures for analyzing the results of calculations.

EVALUASI KINERJA DAN PERBAIKAN STRUKTUR BETON GEDUNG PENDINGIN AIR = EVALUATION ON THE PERFORMANCE OF AND REPAIR OF THE CONCRETE STRUCTURE OF A COOLING WATER TOWER

2019 ◽  
Vol 13 (1) ◽  
pp. 9
Author(s):  
Hendro Ahmad Fauzi
Keyword(s):  
Structural Analysis ◽  
Cooling Water ◽  
Structural Performance ◽  
Structural Element ◽  
Design Strength ◽  
Earthquake Loads ◽  
Evaluation Of Performance ◽  
Quality Testing ◽  
Structure Strength ◽  
Safe Condition

This paper presents the evaluation of performance and strenght ofstructure by visual inspection and quality testing of concrete in the field by using aSchmidt hammer and UPV. The evaluation on the performance of the structure,strength columns, beams and plates refer to SNI-2847-2002, in which theimplementation of earthquake loads was based on SNI-1726-2002.The paperproposes improvements and retrofitting necessary structures. SAP2000 is usedfor structural analysis necessary to obtain the required strength values (Ru).Beton2000 is used for structural analysis of existing conditions in order to get thedesigned strength values (Rn). The structure components are in safe condition ifits design strength is greater or equal than required strength or (Ø.Rn) ≥ Ru.Improvements were made to the structural element by coating and injectionmethods.Keywords : structural performance evaluation, improvement AbstrakMakalah ini menyajikan evaluasi kinerja dan kekuatan struktur denganmetode pemeriksaan secara visual dan pengujian mutu beton di lapangandengan alat Schmidt hammer dan UPV. Evaluasi kinerja struktur, kekuatankolom, balok serta pelat mengacu pada SNI-2847-2002, dengan penerapanbeban gempa berdasarkan SNI-1726-2002, serta memberikan usulan perbaikandan perkuatan struktur yang diperlukan. SAP 2000 digunakan untuk analisisstruktur guna mendapatkan nilai kuat perlu (Ru). Beton 2000 digunakan untukanalisis struktur kondisi existing guna mendapatkan kuat rencana (Rn).Komponen struktur dikatakan aman jika kuat rencana lebih besar atau samadengan kuat rencana atau (ф . Rn) ≥ Ru. Perbaikan elemen struktur dilakukandengan metode coating dan injeksi..Kata kunci : evaluasi kinerja struktur, metode perbaikan

A Study on the Early Detection of Metal Line Bridge Defects Using Wafer Burn-in Stress

2020 ◽  
Author(s):  
Kyunghwui Min ◽  
Hayoung Kwon ◽  
Seihui Lee ◽  
Heeil Hong ◽  
Sungsoo Yim ◽  
...  
Keyword(s):  
Random Access ◽  
System Level ◽  
Production Environment ◽  
Wafer Level ◽  
Metal Line ◽  
Voltage Level ◽  
Voltage Stress ◽  
Scaling Down ◽  
Bridge Failure

Abstract As scaling-down of dynamic random access memory (DRAM) has been continued, the pitch of metal-line already reached sub-50nm where it is hard to define the soft bridge and normal one. Moreover, the metal bridge failure at system level cannot be corrected with in-situ system error-code correction (ECC) modules. In order to screen these failures in the wafer or/and package level electrical tests, high voltage stress methods are necessary. Therefore, accurate stress quantity decided by combination temperature, voltage and time, and effective stress methodologies are essential for high quality and reliability. For a mass production environment, a wafer level burn-in (WBI) can enable multiple word-lines simultaneously and consistently is appropriate. Moreover, we confirmed the actual voltage level on real cells in WBI and optimized stress parameters in terms of time and voltage. Finally, it was proven through the WBI evaluation for over 60k DRAM chips.

scholarly journals Design and Construction of Spud Housing for Floating Dock

2018 ◽  
Vol 159 ◽  
pp. 02060
Author(s):  
Hasanudin Hasanudin ◽  
Ardi Nugroho Yulianto
Keyword(s):  
Yield Point ◽  
Maximum Stress ◽  
Research Study ◽  
The Other ◽  
Maximum Deflection ◽  
Element Analysis ◽  
Steel Material ◽  
Minimum Stress ◽  
Design Calculations ◽  
Safe Condition

A floating dock is a type of pontoon for dry docking ships, possessing floodable buoyancy chambers. The Floating docks have more advantages than the other type of ship docking for maintenance. The purpose of the research study is to design and calculate of spud housing construction for floating dock. The spud housing is used to keep of floating dock in the safe condition. Mild steel material is used to construction of spud housing with yield point 235 x 106 N/m2. Design calculations were done by finite element analysis (FEA). The minimum stress is 1042.36 N/m2 and minimum deflection is 0.447 mm. The maximum stress is 0.142 x 109 N/m2 and maximum deflection is 4.019 mm. The maximum stress is not more than yield point of material.

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