scholarly journals Knowledge-Based Prediction of Load-Carrying Capacity of RC Flat Slab through Neural Network and FEM

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Afaq Ahmad ◽  
Muhammad Usman Arshid ◽  
Toqeer Mahmood ◽  
Naveed Ahmad ◽  
Abdul Waheed ◽  
...  
Keyword(s):  
Neural Network ◽  
Carrying Capacity ◽  
Research Work ◽  
Compressive Force ◽  
Critical Parameters ◽  
Load Carrying Capacity ◽  
Concentrated Load ◽  
Flat Slab ◽  
Load Carrying ◽  
Input Parameters

The present research work aims to compare the results for predicting the ultimate response of Reinforced Concrete (RC) members using Current Design Codes (CDCs), an alternative method based on the Compressive Force Path (CFP) method, and Artificial Neural Network (ANN). For this purpose, the database of 145 samples of RC Flat Slab with the simple supported condition under concentrated load is developed from the latest published work. All the cases studied were Square Concrete Slabs (SCS). The critical parameters used as input for the study were column dimension, cs, depth of the slab, ds, shear span ratio, a v s / d , longitudinal percentage steel ratio, ρls, yield strength of longitudinal steel, fyls, the compressive strength of concrete, fcs, and ultimate load-carrying capacity, Vus. Seven ANN models were trained using different combinations of input parameters and different points of hidden neurons with different activation functions. The results exhibited that SCS-4 was the most optimized ANN model, having the maximum value of R (89%) with the least values of MSE (0.62%) and MAE (6.2%). It did not only reduce the error but also predicted accurate results with the least quantity of input parameters. The predictions obtained from the studied models (i.e., CDCs, CFP, and ANN) exhibited that results obtained using the ANNs model correlated well with the experimental data. Furthermore, the FEM results for the selected cases show the closer result to the ANN predictions.

Fuzzy Sets Theory in Comparison with Stochastic Methods to Analyse Nonlinear Behaviour of a Steel Member under Compression

2005 ◽  
Vol 10 (1) ◽  
pp. 65-75 ◽  
Author(s):  
Z. Kala
Keyword(s):  
Fuzzy Sets ◽  
Carrying Capacity ◽  
Stochastic Methods ◽  
Nonlinear Behaviour ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Input Parameters ◽  
Stochastic Solution ◽  
Fuzzy Solution ◽  
Sets Theory

The load-carrying capacity of the member with imperfections under axial compression is analysed in the present paper. The study is divided into two parts: (i) in the first one, the input parameters are considered to be random numbers (with distribution of probability functions obtained from experimental results and/or tolerance standard), while (ii) in the other one, the input parameters are considered to be fuzzy numbers (with membership functions). The load-carrying capacity was calculated by geometrical nonlinear solution of a beam by means of the finite element method. In the case (ii), the membership function was determined by applying the fuzzy sets, whereas in the case (i), the distribution probability function of load-carrying capacity was determined. For (i) stochastic solution, the numerical simulation Monte Carlo method was applied, whereas for (ii) fuzzy solution, the method of the so-called α cuts was applied. The design load-carrying capacity was determined according to the EC3 and EN1990 standards. The results of the fuzzy, stochastic and deterministic analyses are compared in the concluding part of the paper.

Influence of water contamination in gear lubricants on wear and micro-pitting performance of case carburized gears

2017 ◽  
Vol 69 (4) ◽  
pp. 612-619 ◽  
Author(s):  
Christian Engelhardt ◽  
Jochen Witzig ◽  
Thomas Tobie ◽  
Karsten Stahl
Keyword(s):  
Carrying Capacity ◽  
Research Work ◽  
Load Carrying Capacity ◽  
Wear Performance ◽  
Content Type ◽  
Effect Of Water ◽  
Base Oils ◽  
Load Carrying ◽  
Different Types ◽  
Influence Of Water

Purpose Water can alter the performance of modern gear lubricants by influencing the flank load carrying capacity of gears significantly. The purpose of this paper is to investigate the influence of water contaminations in different kinds of base oils on the micro-pitting and wear performance of case carburized gears. Design/methodology/approach Concerning micro-pitting and wear, tests, based mostly on the following standardized tests, are performed on a Forschungsstelle fuer zahnraeder und getriebebau (FZG)-back-to-back gear test rig: micro-pitting short test Graufleckenkurztest (GFKT) according to DGMK 575 (screening test), micro-pitting test Graufleckentest (GT) according to FVA 54/7 (load stage test and endurance test) and Slow-speed wear test according to DGMK 377. To investigate the effect of water on the gear load carrying capacity dependent on different types of base oils, two polyglycol oils (PG1 and PG2), a polyalphaolefin oil, a mineral oil and an ester oil E are used. Each of these oils are common wind turbine gear oils with a viscosity ISO VG-220. Additionally, a manual transmission fluid with a viscosity of society of automotive engineers (SAE) 75W-85 is tested. Findings Considering the micro-pitting and wear performance, a significant decrease caused by water contaminations could not be detected. Regarding pitting damages, a generally negative influence was observed. This influence was differently distinctive for different base oil types. Especially non-polar lubricants seem to be affected negatively. The documented damages of the tooth flanks confirm this observation. While typical pitting damages appeared in test runs with polar lubricants, the disruption in test runs with non-polar lubricants was more extensive. Based on the experimental investigations, a general model of the damaging mechanisms of water contaminations in lubricants was derived. It is split into three partitions: interaction lubricant–water (effect of water on the molecular structure of base oils and additives), chemical-material-technological (especially corrosive reactions) and tribological influence (effect of water droplets in the contact zone). It has to be considered that the additive package of lubricants affects the influence of water contaminations on the flank load carrying capacity distinctively. An influence of water on the micro-pitting and wear performance in other than the given lubricants cannot be excluded. Originality/value While former research work was focused more on the effects of water in mineral oils, investigations concerning different types of base oils as well as different types of damages were carried out within this research project.

scholarly journals Strengthening of Reinforced Concrete Beams Subjected to Concentrated Loads

2022 ◽  
Author(s):  
Paolo Foraboschi
Keyword(s):  
Reinforced Concrete ◽  
Carrying Capacity ◽  
Concrete Beams ◽  
Shear Capacity ◽  
Reinforced Concrete Beams ◽  
Load Carrying Capacity ◽  
Reinforced Concrete Structure ◽  
Concentrated Loads ◽  
Concentrated Load ◽  
Load Carrying

Renovation, restoration, remodeling, refurbishment, and retrofitting of build-ings often imply modifying the behavior of the structural system. Modification sometimes includes applying forces (i.e., concentrated loads) to beams that before were subjected to distributed loads only. For a reinforced concrete structure, the new condition causes a beam to bear a concentrated load with the crack pattern that was produced by the distributed loads that acted in the past. If the concentrated load is applied at or near the beam’s midspan, the new shear demand reaches the maximum around the midspan. But around the midspan, the cracks are vertical or quasi-vertical, and no inclined bar is present. So, the actual shear capacity around the midspan not only is low, but also can be substantially lower than the new demand. In order to bring the beam capacity up to the demand, fiber-reinforced-polymer composites can be used. This paper presents a design method to increase the concentrated load-carrying capacity of reinforced concrete beams whose load distribution has to be changed from distributed to concentrated, and an analytical model to pre-dict the concentrated load-carrying capacity of a beam in the strengthened state.

Progressive Failure Analysis of an Integral Composite Joint for Thrust Reverser Cascade

2019 ◽  
Vol 795 ◽  
pp. 325-332
Author(s):  
Ji Shen Yang ◽  
Hong Yu Qi ◽  
Xiao Guang Yang ◽  
Duo Qi Shi
Keyword(s):  
Carrying Capacity ◽  
Composite Structure ◽  
Progressive Failure ◽  
Damage Model ◽  
Research Work ◽  
Failure Behavior ◽  
Load Carrying Capacity ◽  
Composite Joint ◽  
Bending Load ◽  
Load Carrying

The research work in this paper is focused on studying the failure behavior of an integral π-shaped laminated composite structure subjected to a bending load. A progressive damage model based on the 3D Tsai-Wu failure criterion and a developed gradual degradation model was employed to simulate and assess the load-carrying capacity, the onset and propagation of damage, and the failure mechanisms. For this unique π-shaped composite structure, disbonding was found to be the dominant damage mode under bending load, and the approximate maximum load could be maintained for a brief time during the final failure due to the gradual loss nature of the load-carrying capacity. The extent of damage was found to be more serious on the side of Rib II compared to the other side.

Analysis of shear behavior between old concrete and fiber concrete

2021 ◽  
Author(s):  
Martin Vavruš ◽  
Peter Koteš ◽  
František Bahleda ◽  
Jozef Jošt
Keyword(s):  
Carrying Capacity ◽  
Research Work ◽  
Concrete Structures ◽  
Mechanical Damage ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Fiber Concrete ◽  
Different Types ◽  
Thawing And Freezing Cycles

AbstractConcrete structures that are influenced by degradation, overloading, the thawing, and freezing cycles, corrosion of reinforced bars, should be repaired or strengthened. Each of the mentioned influences lead to decreased load-carrying capacity of the structure or its member. Exceeding the load-carrying capacity leads to mechanical damage of members or excessive deformation. The damaged member has to be strengthened to the required level of reliability and load-carrying capacity. There exist many types and methods of strengthening the columns. This research work deals with strengthening of columns by concreting a new layer of fiber concrete. When applying that type of strengthening, it is necessary to assure the contact between the old layer and the new one. The paper deals with analysis of different types of contacts and determination of their parametric values.

Floor trusses subjected to a concentrated load

1984 ◽  
Vol 11 (2) ◽  
pp. 355-362
Author(s):  
Murray C. Temple ◽  
Dan Racic ◽  
Sandy Pavlica
Keyword(s):  
Carrying Capacity ◽  
Bottom Flange ◽  
Load Carrying Capacity ◽  
Concentrated Load ◽  
Simple Modification ◽  
Box Section ◽  
Distributed Load ◽  
Load Carrying ◽  
The Subject ◽  
Solid Piece

The results of extensive testing of floor joists subjected to a concentrated load are presented. These floor joists are constructed with 2 × 4 (38 × 89 mm) flanges and steel V web members. The load-carrying capacity of these joists when subjected to a uniformly distributed load has been investigated previously. These joists, however, are often subjected to a concentrated load as the result of a floor opening, and this is the subject of this investigation. The use of this floor truss is similar to two 2 × 12 (38 × 286 mm) joists arranged back-to-back.The floor trusses were modified by adding extra material to the joists and by nailing the exposed bottom flange grips of the V web members. Adding the extra material resulted in the formation of a box section over part of the span. Another method, adding a solid piece of lumber inside the truss to form an I section, was also tried. A concentrated load was applied to the reinforced truss and the truss was loaded to failure. A significant improvement in load-carrying capacity was achieved through a simple modification to an ordinary floor truss.

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