scholarly journals Finite Element Model-Based Weight-Over Process Philosophy for Bridge Loading Capacity Evaluation and Rating Factor Estimation

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Ali Karimpour ◽  
Salam Rahmatalla ◽  
Hossein Bolboli Ghadikolaee
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Load Capacity ◽  
Element Model ◽  
Process Philosophy ◽  
Loading Capacity ◽  
Load Testing ◽  
Capacity Evaluation ◽  
Rating Factor ◽  
Factor Estimation

Existing rating methods estimate bridge loading capacity and demand from secondary actions due to live loads in the primary structural components. In these methods, uniaxial yielding stress is traditionally used to detect component capacity using either stress quantities or shear-moment actions to compute the capacity demand of the bridge. These approximations can lead to uncertainties in load capacity estimation. This article presents the weight-over process (WOP), a novel computer-aided approach to bridge loading capacity evaluation based on tonnage and rating factor estimation. WOP is expected to capture different forms of failure in a more general manner than existing methods. In WOP, a bridge finite element model (FEM) is discretized into many sections and element sets, each containing a single material type, and each assigned a suitable 3D failure criterion. Then, factored gross vehicle weights (GVWs) are incrementally imposed on the bridge FEM with those predefined ultimate unfavored loading scenarios in a manner similar to proof load testing. WOP code runs nonlinear analysis at each increment until a stopping criterion is met. Two representative bridges were selected to confirm WOP’s feasibility and efficacy. The results showed that WOP-predicted values at the interior girders were between those of the conventional AASHTO and the nondestructive testing (NDT) strain measurement methods. That may put WOP in a favorable zone as a new method that is less conservative than AASHTO but more conservative than real NDT testing.

Optimization Design of a New Heavy-Duty Self-Unloading Semi-Trailer

2011 ◽  
Vol 317-319 ◽  
pp. 2373-2377
Author(s):  
Guo Juan Shang ◽  
Gen Li Shan ◽  
Xi Juan Qi
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Optimization Design ◽  
Market Research ◽  
High Efficiency ◽  
Three Dimensional ◽  
Element Model ◽  
Loading Capacity ◽  
Heavy Duty ◽  
The Finite Element Model

Based on sufficient market research, a new model of self-unloading semi-trailer, whose maximum loading capacity is 30 tons, has been designed. The paper describes its overall structure, the three-dimensional diorama model and the finite element model of the frame. Based on the analysis of the models and the results of the calculation, the parameters of the frame are optimized. The advantages of the new design are as follows: the new design makes the most of the advantages of self-unloading trailers and semi-trailers, that is, self-unloading, security, stability, high efficiency, environmental protection.

scholarly journals Numerical analysis of concrete-filled spiral welded stainless steel tubes subjected to compression

2018 ◽  
Author(s):  
Dongxu Li ◽  
Brian Uy ◽  
Farhad Aslani ◽  
Chao Hou
Keyword(s):  
Finite Element ◽  
Stainless Steel ◽  
Finite Element Model ◽  
Mechanical Performance ◽  
Load Capacity ◽  
Element Model ◽  
Experimental Program ◽  
Design Parameters ◽  
Steel Tubes ◽  
Finite Element Software

Spiral welded stainless tubes are produced by helical welding of a continuous strip of stainless steel. Recently, concrete-filled spiral welded stainless steel tubes have found increasing application in the construction industry due to their ease of fabrication and aesthetic appeal. However, an in-depth understanding of the behaviour of this type of structure is still needed due to the lack of proper design guidance and insufficient experimental verification. In this paper, the mechanical performance of concrete-filled spiral welded stainless steel tubes will be numerically investigated with a commercial finite element software package, through which an experimental program can be designed properly. Specifically, the proposed finite element models take into account the effects of material and geometric nonlinearities. Moreover, the initial imperfections of stainless steel tubes and the form of helical welding will be appropriately included. Enhancement of the understanding of the analysis results can be achieved by extending results through a series of parametric studies based on the developed finite element model. Thus, the effects of various design parameters will be further evaluated by using the developed finite element model. Furthermore, for the purposes of wide application of such types of structure, the accuracy of the behaviour prediction in terms of ultimate strength based on current design codes will be studied. The authors herein compared the load capacity between the finite element analysis results and the existing codes of practice.

scholarly journals A Pneumatic Novel Combined Soft Robotic Gripper with High Load Capacity and Large Grasping Range

Actuators ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 3
Author(s):  
Dan Wang ◽  
Xiaojun Wu ◽  
Jinhua Zhang ◽  
Yangyang Du
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Material Properties ◽  
Load Capacity ◽  
Element Model ◽  
High Load ◽  
Minimum Diameter ◽  
Practical Applications ◽  
Soft Actuator ◽  
High Load Capacity

Pneumatic soft grippers have been widely studied. However, the structures and material properties of existing pneumatic soft grippers limit their load capacity and manipulation range. In this article, inspired by sea lampreys, we present a pneumatic novel combined soft gripper to achieve a high load capacity and a large grasping range. This soft gripper consists of a cylindrical soft actuator and a detachable sucker. Three internal air chambers of the cylindrical soft actuator are inflated, which enables them to hold objects. Under vacuum pressure, the cylindrical soft actuator and the detachable sucker can both adsorb objects. A finite element model was constructed to simulate three inflation chambers for predicting the grasping range of the cylindrical soft actuator. The validity of the finite element model was established by an experiment. The mechanism of holding force and adsorption force were analyzed. Several groups of experiments were conducted to determine adsorption range, holding force, and adsorption force. In addition, practical applications further indicated that the novel combined soft gripper has a high load capacity (10.85 kg) at a low pressure (16 kPa) and a large grasping range (minimum diameter of the object: d = 6 mm), being able to lift a variety of objects with different weights, material properties, and shapes.

scholarly journals Analysis of RC Continuous Beams Strengthened with FRP Plates: A Finite Element Model

2016 ◽  
Vol 2 (11) ◽  
pp. 576-589 ◽  
Author(s):  
Mohamed A. Sakr ◽  
Tarek M. Khalifa ◽  
Walid N. Mansour
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Load Capacity ◽  
Element Model ◽  
Mixed Mode Fracture ◽  
Zone Model ◽  
Fe Model ◽  
Rc Beams ◽  
Continuous Beams ◽  
Externally Bonded

Strengthening of reinforced concrete (RC) beams with externally bonded fibre reinforced polymer (FRP) plates/sheets technique has become widespread in the last two decades. Although a great deal of research has been conducted on simply supported RC beams, a few studies have been carried out on continuous beams strengthened with FRP composites.  This paper presents a simple uniaxial nonlinear finite-element model (UNFEM) that is able to accurately estimate the load-carrying capacity and the behaviour of RC continuous beams flexurally strengthened with externally bonded FRP plates on both of the upper and lower fibres. A 21-degree of freedom element is proposed with layer-discretization of the cross-sections for finite element (FE) modelling. Realistic nonlinear constitutive relations are employed to describe the stress-strain behaviour of each component of the strengthened beam. The FE model is based on nonlinear fracture mechanics. The interfacial shear and normal stresses in the adhesive layer are presented using an analytical uncoupled cohesive zone model with a mixed-mode fracture criterion. The results of the proposed FE model are verified by comparison with various selected experimental measurements available in the literature. The numerical results of the plated beams (beams strengthened with FRP plates) agreed very well with the experimental results. The use of FRP increased the ultimate load capacity up to 100 % compared with the non-strengthened beams as occurred in series (S). The major objective of the current model is to help engineers’ model FRP-strengthened RC continuous beams in a simple manner.

Evaluation for RC Column Confined Partially with Externally FRP Wrapping Sheet Using Nonlinear FE Analysis

2019 ◽  
Vol 972 ◽  
pp. 129-133
Author(s):  
Yasmeen Taleb Obaidat
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Finite Element Model ◽  
Load Capacity ◽  
Element Model ◽  
Material Behavior ◽  
Nonlinear Material ◽  
Concrete Column ◽  
Reinforced Concrete Column ◽  
Number Of Layers

Little research has been carried out in validating, fiber reinforced polymer (FRP) concrete strengthened column and the effective using partial wrapping. Also the effect of several parameter on strengthen column using the partial wrapping sheet of desired width and thickness around column have not been found out. To this end, a nonlinear 3D finite element model has been developed in current study for CFRP strengthened reinforced concrete column to simulate the behavior accompanied by the effect of partial wrapping with emphasis on load capacity and failure mode. The finite element simulation of CFRP strengthened RC columns is performed using commercial finite element program ABAQUS. Modelling was conducted on reinforced concrete columns with dimensions of 160 x 250 x 960 mm. The finite element model incorporates the nonlinear material behavior of concrete, bilinear stress-strain curve of steel and linear elastic behavior of CFRP material. The concrete was modeled using a plastic damage model. The performance of the FE model was studied by simulating experimental columns from the literature. The load, and strain of CFRP obtained from the FE study were compared with the corresponding experimental results. The FEM results agreed well with the experiments. In addition, to enhance our understanding of the behavior of strengthened reinforced concrete column capacity using partial wrapping the effect of changing the spacing between the CFRP sheets and number of layers were examined. The increase number of layers and decrease spacing give a higher ultimate load capacity, and delay the failure.

Validation of a Computer Model for Flexible Pipe Crushing Resistance Calculations

2008 ◽  
Author(s):  
Aline Malcorps ◽  
Antoine Felix-Henry
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Plastic Material ◽  
Load Capacity ◽  
Permanent Deformation ◽  
Element Model ◽  
Design Criterion ◽  
Internal Diameter ◽  
Flexible Pipe ◽  
Offshore Field

Several types of laying equipments are used to install flexible pipelines for offshore field developments. These pipelines installation tools apply generally compressive radial forces to hold the pipe suspended weight. The deeper the pipeline has to be laid, the higher is its suspended weight and therefore the higher these radial loads need to be. As each flexible pipe construction is optimized for each field application, a design methodology is necessary to be able to evaluate the radial load acceptable by the flexible pipe. The failure mode associated with this type of loads is an instability thought to be similar to the hydrostatic collapse mode. Therefore an adequate design safety factor has to be considered. The water depth of offshore field developments becoming ever deeper, the resistance of the flexible pipe to installation loads becomes often a driving design criterion. A finite element model to address this type of loading has been developed and improved over the past years. To avoid over-sizing the flexible pipe with current design approach, this finite element model needed to be improved for the latest materials used and for higher crushing loads. To this effect, a new powerful test bench with a crushing load capacity of 1200 tons over one meter has been designed, procured and is now operational. It can handle pipes from 4" to 19" internal diameter. Many types of flexible pipe samples have been tested up to permanent deformation using bi-, tri- and quadri-caterpillar tensioners. The results of these tests have been used to validate a new finite element model using in particular non-linear elasto-plastic material laws. In this paper, several test results will be presented and compared with the calculations. The relevance of different possible design criteria depending on the type of loading regime, the slenderness of the pipe and the number of radially resistant layers, will also be discussed. This new model is operational and allows to optimize the flexible pipe design in particular for ultra-deep water applications down to 2500m or more.

scholarly journals Development of a Friction-Driven Finite Element Model to Simulate the Load Bridging Effect of Unit Loads Stored in Warehouse Racks

2021 ◽  
Vol 11 (7) ◽  
pp. 3029
Author(s):  
Eduardo Molina ◽  
Laszlo Horvath ◽  
Robert L. West
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Design Methodology ◽  
Load Capacity ◽  
Element Model ◽  
Raw Material ◽  
Affecting Factors ◽  
Unit Load ◽  
Load Beam ◽  
Bending Response

Current pallet design methodology frequently underestimates the load capacity of the pallet by assuming the payload is uniformly distributed and flexible. By considering the effect of payload characteristics and their interactions during pallet design, the structure of the pallets can be optimized, and raw material consumption reduced. The objective of this study was to develop and validate a finite element model capable of simulating the bending of a generic pallet while supporting a payload made of corrugated boxes and stored on a warehouse load beam rack. The model was generalized in order to maximize its applicability in unit load design. Using a two-dimensional, nonlinear, implicit dynamic model, it allowed for the evaluation of the effect of different payload configurations on the pallet bending response. The model accurately predicted the deflection of the pallet segment and the movement of the packages for a unit load segment with three or four columns of boxes supported in a warehouse rack support. Further refinement of the model would be required to predict the behavior of unit loads carrying larger boxes. The model presented provides an efficient solution to the study of the affecting factors to ultimately optimize pallet design. Such a model has not been previously developed. The model successfully acts as a tool to study and predict the load bridging performance of unit loads requiring only widely available input data, therefore providing a general solution.

Sign in / Sign up

Export Citation Format

Share Document