THE EFFECT OF SHEAR REINFORCEMENT RATIO ON PRESTRESSED CONCRETE BEAMS SUBJECTED TO IMPACT LOAD

2018 ◽  
Vol 5 (1) ◽  
Author(s):  
Mohamad Elani ◽  
Yehya Temsah ◽  
Hassan Ghanem ◽  
Ali Jahami ◽  
Youmn Al Rawi
Keyword(s):  
Finite Element ◽  
Prestressed Concrete ◽  
Impact Load ◽  
Nonlinear Behavior ◽  
Element Model ◽  
Shear Reinforcement ◽  
Dynamic Increase Factor ◽  
Concrete Damage ◽  
Different Response ◽  
The Impact

Structural elements subjected to impact loads have a different response than those subjected to static loads. This research studied the effect of using shear reinforcement to reduce the local damage occurred when an impact load applied on a prestressed concrete beam. An accurate finite element model was provided for the analysis using the advanced volumetric finite element modeling program (ABAQUS). The concrete material was defined using the built in concrete damage plasticity model (CDP), that considers the nonlinear behavior of concrete when subjected to dynamic loading. All material properties were modified using the dynamic increase factor (DIF) to consider the effect of impact loading. It was realized that the failure was concentrated in the impact zone. However, using shear reinforcement reduced the permanent damage occurred due to impact.

The Analysis on Suspension of Fire Robot Based on FEA

2014 ◽  
Vol 716-717 ◽  
pp. 1536-1539
Author(s):  
Yan Xu ◽  
Shu Fang ◽  
Jian Qiao Fu
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Stress Condition ◽  
Impact Load ◽  
Element Model ◽  
Force Condition ◽  
Environmental Adaptability ◽  
The Impact ◽  
Suspension Structure

The suspension of fire robot, one of necessary components, directly impacts the environmental adaptability, and the strength of suspension has great importance to the life of robot. In the paper, the structure and the stress condition of the suspension was analyzed. The force condition of suspension is simplified as a 2-D diagram, the load acting on the elbow were simplified in two direction, A finite element model, which simulated the impact load and optimized the design of suspension, was established, and the result of the simulation shows the suspension structure is reasonable and the strength of the component is enough.

scholarly journals Mechanical Response of Typical Cement Concrete Pavements under Impact Loading

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Ding Fei ◽  
Yin Yan ◽  
Cai Liangcai ◽  
Tang Yaohong ◽  
Wang Xuancang
Keyword(s):  
Finite Element ◽  
Impact Loading ◽  
Mechanical Response ◽  
Impact Load ◽  
Damage Model ◽  
Three Dimensional ◽  
Element Model ◽  
Concrete Pavements ◽  
Cement Concrete ◽  
Concrete Damage

In order to study the mechanical response of cement concrete pavements under impact loading, four types of typical cement concrete pavement structures are investigated experimentally and numerically under an impact load. Full-scale three-dimensional pavement slots are tested under an impact load and are monitored for the mechanical characteristics including the deflection of the pavement surface layer, the strain distribution at the bottom of the slab, and the plastic damage and cracking under the dynamic impact load. Numerical analysis is performed by developing a three-dimensional finite element model and by utilizing a cement concrete damage model. The results show that the calculation results based on the cement concrete damage model are in reasonable agreement with the experimental results based on the three-dimensional test slot experiment. The peak values of stress and strain as monitored by the sensors are analyzed and compared with the numerical results, indicating that the errors of numerical results from the proposed model are mostly within 10%. The rationality of the finite element model is verified, and the model is expected to be a suitable reference for the analysis and design of cement concrete pavements.

scholarly journals Numerical analysis of the behavior of a three-layer honeycomb panel with interlayer defects under action of dynamic load

2021 ◽  
Vol 17 (4) ◽  
pp. 357-365
Author(s):  
Aleksandr L. Medvedskiy ◽  
Mikhail I. Martirosov ◽  
Anton V. Khomchenko ◽  
Darina V. Dedova
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Impact Load ◽  
Geometric Model ◽  
Three Dimensional ◽  
Element Model ◽  
Failure Criteria ◽  
Stress Fields ◽  
The Impact ◽  
Honeycomb Panel

The aim of the work is to study the effect of interlayer defects of the bundle type on the behavior of a rectangular flat three-layer panel with a honeycomb filler under the influence of a dynamic impact load. Methods. The problem was solved numerically using the finite element method in the Simcenter Femap and LS-DYNA (Livermore Software Technology Corp.) software complexes. For this purpose, a geometric model of a panel with a honeycomb placeholder was developed. Based on the geometric model, a finite element model of the panel was created using three-dimensional finite elements. In the software complexes, the finite element model was calculated under specified boundary conditions, then the stress fields and fracture indices in the panel were determined, taking into account and without taking into account damage. Results. The stress fields in the panel are numerically determined with and without defects. The fields of the failure indices of the panel layers under the impact load are investigated using various failure criteria (Puck, Hashin, LaRC03 (Langley Research Center)) of polymer composite materials. The analysis of the influence of a defect on the behavior of a honeycomb panel under the impact load is carried out.

scholarly journals An investigation of the effects of osteoporosis, impact intensity and orientation on human femur injuries: a parametric finite element study

2019 ◽  
Vol 6 (1) ◽  
pp. 28-32
Author(s):  
Ramin Shahbad ◽  
Mohsen Mortazavi ◽  
Fereshteh Alizadeh-Fard ◽  
Zeinab Mohammadi ◽  
Fatemeh Alavi ◽  
...  
Keyword(s):  
Finite Element ◽  
Bone Density ◽  
Femoral Neck ◽  
Human Body ◽  
Impact Load ◽  
Element Model ◽  
Effective Parameters ◽  
Large Numbers ◽  
The Impact ◽  
High Mechanical Stress

Objective: Femur is the strongest, longest and heaviest bone in the human body. Due to the great importance of femur in human body, its injury may cause large numbers of disabilities and mortality. Considering various effective parameters such as mechanical properties, geometry, loading configuration, etc. can propel the study to the trustable results. Methods: A 3D finite element model of the femur was subjected to different impact loading and orientations and also material properties. In addition to a reference healthy model of analysis, a total of 14 cases including four different loading conditions, six different bone density conditions and four different load orientations were considered. Results: Findings showed that the models with higher bone density cannot considerably reduce the stress under the impact loadings but porous models receive high mechanical stress which the bone prone to injury. The stress and displacement of the bone model received more values distributed through the femoral neck. Conclusion: Porous bone models had greater stress values under an impact load. Higher and faster impacts may create multi-fracture breaks of the femur. The inferior femoral neck regions are the most vulnerable part in response to the impacts.

Fibre-Reinforced Polymers under Impact Load

2006 ◽  
Vol 326-328 ◽  
pp. 1563-1568 ◽  
Author(s):  
Ch.R. Koenig ◽  
D.H. Mueller ◽  
J. Mueller ◽  
Mircea Calomfirescu
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Impact Load ◽  
Composite Plates ◽  
Element Model ◽  
Structural Failure ◽  
Reinforced Polymers ◽  
The University ◽  
The Impact ◽  
The Finite Element Model

Structural failure of fibre-reinforced polymers (FRP) caused by impact is an important factor in product development for the aircraft industry. Therefore it is necessary to obtain knowledge of the mechanisms and of the material loading during and shortly after an impact load. On account of this a Finite-Element-Model was developed with the goal to deduce design rules for impact tolerant composite materials. To verify and validate the Finite-Element-Model it is essential to have information of the state of stress on the surface of the FRP shortly after the impact. An impact test device was developed at the University of Bremen. The time variable, stress and strain conditions in composite plates are measured using photoelastic technique, strain gauges and holographic interferometry.

Investigation on the shaft voltage generation of large synchronous turboalternators

2020 ◽  
Vol 39 (5) ◽  
pp. 1145-1156
Author(s):  
Kevin Darques ◽  
Abdelmounaïm Tounzi ◽  
Yvonnick Le-menach ◽  
Karim Beddek
Keyword(s):  
Finite Element ◽  
Design Methodology ◽  
Short Circuit ◽  
Element Model ◽  
Stator Winding ◽  
Content Type ◽  
Voltage Generation ◽  
The Impact ◽  
Investigation Process ◽  
Circulating Currents

Purpose This paper aims to go deeper on the analysis of the shaft voltage of large turbogenerators. The main interest of this study is the investigation process developed. Design/methodology/approach The analysis of the shaft voltage because of several defects is based on a two-dimensional (2D) finite element modeling. This 2D finite element model is used to determine the shaft voltage because of eccentricities or rotor short-circuit. Findings Dynamic eccentricities and rotor short circuit do not have an inherent impact on the shaft voltage. Circulating currents in the stator winding because of defects impact the shaft voltage. Originality/value The original value of this paper is the investigation process developed. This study proposes to quantify the impact of a smooth stator and then to explore the contribution of the real stator winding on the shaft voltage.

Behavior of Structures Using Simple Plastic Hinge Theory

1994 ◽  
Author(s):  
Ramakrishnan Maruthayappan ◽  
Hamid M. Lankarani
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Cantilever Beam ◽  
Reliable Method ◽  
Plastic Hinge ◽  
Element Model ◽  
Finite Element Models ◽  
Computational Program ◽  
Hinge Model ◽  
The Impact

Abstract The behavior of structures under the impact or crash situations demands an efficient modeling of the system for its behavior to be predicted close to practical situations. The various formulations that are possible to model such systems are spring mass models, finite element models and plastic hinge models. Of these three techniques, the plastic hinge theory offers a more accurate model compared to the spring mass formulation and is much simpler than the finite element models. Therefore, it is desired to model the structure using plastic hinges and to use a computational program to predict the behavior of structures. In this paper, the behavior of some simple structures, ranging from an elementary cantilever beam to a torque box are predicted. It is also shown that the plastic hinge theory is a reliable method by comparing the results obtained from a plastic hinge model of an aviation seat structure with that obtained from a finite element model.

Dynamic Ultimate Strength Characteristics of Stiffened Plates Subjected to the In-Plane Impact Load and Lateral Pressure

2021 ◽  
Author(s):  
Qiang Zhong ◽  
De-yu Wang
Keyword(s):  
Finite Element ◽  
Ultimate Strength ◽  
Lateral Pressure ◽  
Impact Load ◽  
Strength Characteristics ◽  
Stiffened Plates ◽  
Strength Theory ◽  
Explicit Finite Element ◽  
Static Conditions ◽  
The Impact

Abstract Dynamic capacity is totally different from quasi-static capacity of ship structural components, although most ultimate strength analyses at present by researchers are performed under quasi-static conditions. To investigate the dynamic ultimate strength characteristics, the dynamic ultimate strength analyses of stiffened plates subjected to impact load were studied based on a 3-D nonlinear explicit finite element method (FEM) in this paper. The impact load in the present work is characterized as a half-sine function. A series of nonlinear finite element analyses are carried out using Budiansky-Roth (B-R) criterion. The influence of impact durations, model ranges, boundary conditions, initial imperfections and impact loads on the dynamic ultimate strength of stiffened plates are discussed. In addition, the ultimate strength of stiffened plates under the in-plane impact combined with lateral pressure was also calculated, which shows lateral pressure has a negligible effect on the dynamic ultimate strength of stiffened plates subjected to the impact load with short durations. Other important conclusions can be obtained from this paper, which are useful insights for the development of ultimate strength theory of ship structures and lay a good foundation for the study of dynamic ultimate strength in the future.

Simulation Analysis of Secondary-Load Rc Square Columns Strengthened with IFRP

2014 ◽  
Vol 501-504 ◽  
pp. 578-582
Author(s):  
Liang Hsu ◽  
Ming Long Hu ◽  
Jun Zhi Zhang
Keyword(s):  
Finite Element ◽  
Simulation Analysis ◽  
Element Model ◽  
Fiber Reinforced Polymer ◽  
Experimental Result ◽  
Compression Process ◽  
Reinforced Polymer ◽  
Secondary Load ◽  
The Impact ◽  
The Finite Element Model

Considering secondary load, simulate the axial compression process of reinforced concrete square columns strengthened with igneous rock fiber reinforced polymer with Abaqus. Make a comparison between the simulation result and experimental result. The finite-element model can simulate the experiment preferably. And the impact of lagged strain is very obvious.

Additional Damping Conditions Analysis and Calculation for Exciting Force and External Load

2013 ◽  
Vol 579-580 ◽  
pp. 507-511
Author(s):  
Yi Xiang Liu ◽  
Yong Mei Wang
Keyword(s):  
Finite Element ◽  
Element Model ◽  
Structure Design ◽  
Exciting Force ◽  
Reduction Gear ◽  
Solid Model ◽  
Gear Noise ◽  
Force Reduction ◽  
And Control ◽  
The Impact

This paper firstly starting mechanism of vibration and noise from gear, gear noise mechanism is explained, and analyze the factors and the impact of noise on the gear reducer. Secondly, the establishment of a complete solid model of gear reducer and reducer model for finite element model, the reduction gear box gear reducer of modal analysis and finite element modal calculation, and points out the dynamic analysis of structure, size and weight factor is proportional to the reciprocal of the modal frequencies of each mode is the with the frequency is low, that is, the greater the weight. Once again, the main measure of load and control of gear noise of gear is analyzed, including the calculation, for exciting force reduction gear reducer gear load computation. The analysis and calculation are the theoretical basis of gear structure design and its performance evaluation.

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