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.

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.

scholarly journals OPTIMIZATION OF SIMPLY SUPPORTED CASTELLATED I-BEAMS LOADED BY A UNIFORMLY DISTRIBUTED LOAD

2019 ◽  
Vol 15 (4) ◽  
pp. 58-65
Author(s):  
Oleg Goryachevskiy
Keyword(s):  
Carrying Capacity ◽  
Descent Method ◽  
Geometric Parameters ◽  
Load Carrying Capacity ◽  
Coordinate Descent Method ◽  
Simply Supported ◽  
Distributed Load ◽  
Load Carrying ◽  
The Stability ◽  
Plastic Steel

The paper discusses the problem of optimizing the geometric parameters of simply supported I-beams in order to maximize their load carrying capacity. Numerical simulation of various types of failure of castellated I- beams with ideal elastic-plastic steel is carried out. The stability of the wall, the strength of the welds and flanges, depending on the geometric parameters investigated. Using the coordinate descent method, the optimization prob­lem is solved for nine design schemes with respect to the section height and the weld length. It was revealed that in short beams the section height should be less and the weld length longer, in contrast to long beams.

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.

Influence of Yield Strength Variability over Cross-Section to Steel Beam Load-Carrying Capacity

2005 ◽  
Vol 10 (2) ◽  
pp. 151-160 ◽  
Author(s):  
J. Kala ◽  
Z. Kala
Keyword(s):  
Yield Strength ◽  
Cross Section ◽  
Carrying Capacity ◽  
Bending Moment ◽  
Statistical Characteristics ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Strength Variability ◽  
Hot Rolled ◽  
Hot Rolled Steel

Authors of article analysed influence of variability of yield strength over cross-section of hot rolled steel member to its load-carrying capacity. In calculation models, the yield strength is usually taken as constant. But yield strength of a steel hot-rolled beam is generally a random quantity. Not only the whole beam but also its parts have slightly different material characteristics. According to the results of more accurate measurements, the statistical characteristics of the material taken from various cross-section points (e.g. from a web and a flange) are, however, more or less different. This variation is described by one dimensional random field. The load-carrying capacity of the beam IPE300 under bending moment at its ends with the lateral buckling influence included is analysed, nondimensional slenderness according to EC3 is λ¯ = 0.6. For this relatively low slender beam the influence of the yield strength on the load-carrying capacity is large. Also the influence of all the other imperfections as accurately as possible, the load-carrying capacity was determined by geometrically and materially nonlinear solution of very accurate FEM model by the ANSYS programme.

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.

Pavement Damage Due to Conventional and New Generation of Wide-Base Super Single Tires

2005 ◽  
Vol 33 (4) ◽  
pp. 210-226 ◽  
Author(s):  
I. L. Al-Qadi ◽  
M. A. Elseifi ◽  
P. J. Yoo ◽  
I. Janajreh
Keyword(s):  
Carrying Capacity ◽  
Material Properties ◽  
Three Dimensional ◽  
Fe Analysis ◽  
Load Carrying Capacity ◽  
Inflation Pressure ◽  
3D Finite Element ◽  
Load Carrying ◽  
Pavement Damage ◽  
New Generation

Abstract The objective of this study was to quantify pavement damage due to a conventional (385/65R22.5) and a new generation of wide-base (445/50R22.5) tires using three-dimensional (3D) finite element (FE) analysis. The investigated new generation of wide-base tires has wider treads and greater load-carrying capacity than the conventional wide-base tire. In addition, the contact patch is less sensitive to loading and is especially designed to operate at 690kPa inflation pressure at 121km/hr speed for full load of 151kN tandem axle. The developed FE models simulated the tread sizes and applicable contact pressure for each tread and utilized laboratory-measured pavement material properties. In addition, the models were calibrated and properly validated using field-measured stresses and strains. Comparison was established between the two wide-base tire types and the dual-tire assembly. Results indicated that the 445/50R22.5 wide-base tire would cause more fatigue damage, approximately the same rutting damage and less surface-initiated top-down cracking than the conventional dual-tire assembly. On the other hand, the conventional 385/65R22.5 wide-base tire, which was introduced more than two decades ago, caused the most damage.

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