scholarly journals Strength and Stiffness Behavior of Earthquake Resistant Pedestrian LVL Timber Bridge

2021 ◽  
Vol 11 (2) ◽  
pp. 53-57
Author(s):  
Bernardinus Herbudiman ◽  
Delima Delima ◽  
Yosafat Aji Pranata
Keyword(s):  
Environmental Damage ◽  
Bridge Structure ◽  
Element Analysis ◽  
Cross Sectional ◽  
Bridge Superstructures ◽  
Cross Sectional Dimension ◽  
Earthquake Resistant ◽  
Beam Type ◽  
The Cross ◽  
Strength And Stiffness

A bridge is a structure which is used to connect two areas separate by obstacles. The environmental damage caused a number of reductions in the production of timber, and by that, the LVL timber which is a high quality processed or engineered timber is chosen. This research determined the design of the timber bridge structure for pedestrian with simple beam type and earthquake resistant. The load in this bridge is referring to the SNI 1725:2016 and SNI 2833:2008, the design of the girder and the connection is referring to SNI 7973:2013, and the deflection is referring to the LFRD for Highway Bridge Superstructures. The timber bridge is designed to have a span of 10 metres long and 3 metres wide. The modeling and designing of the wooden bridge are using an application called SAP2000 based on finite element analysis. Result obtained from this research indicated that the longitudinal dimension of the girder is 360 mm x 630 mm and the cross sectional dimension is 180 mm x 270 mm. The number of bolts and lock screws needed on the connection among the longitudinal girders are 40 pieces, between the longitudinal girders and the cross sectional girders is three pieces, and between the railing and the slab are two pieces. Based on the stiffness review, the results showed that the bridge deflection that occurred was lower than the permit deflection

scholarly journals Analisis Numerik Kuat Lentur Balok Support Beam Curve Tile Beton Semi Pracetak Dengan Variasi Panjang Bentangan

2020 ◽  
Vol 8 (2) ◽  
pp. 61-69
Author(s):  
Yoga Ornando ◽  
Ismeddiyanto ◽  
Iskandar Romey Sitompul
Keyword(s):  
Precast Concrete ◽  
Bending Moment ◽  
Maximum Load ◽  
Crack Pattern ◽  
Beam Length ◽  
Pure Bending ◽  
Element Analysis ◽  
Cross Sectional ◽  
Cross Sectional Dimension ◽  
The Cross

Semi precast slab is a combination of precast concrete which consist of the support beam and curve tile with the cast in place concrete. During the working process, support beam will support the entire load until the slab becomes solid. The study aims to identify the effect of using variations of support beam length towards deflection-load relationship, moment-curvature, crack pattern and cross-sectional dimensions caused by pure bending moments with the same maximum load. The variations of the support beam length are L = 3000 mm, L = 4000 mm, L = 5000 mm and L = 6000 mm which can affect the cross-sectional dimensions of the support beam. The method used in this study was the numerical method by using Abaqus 6.14 CAE software. Abaqus is one of the finite element analysis (FEA) programs to model and analysis the elements of the structure. The loading applied was an axial load which has increased until the support beam failed. The numerical analysis results are the increase of cross section dimension as the increasing of support beam length. The cross-sectional dimension are 100 mm x 60 mm; 110 mm x 65 mm; 110 mm x 70 mm; and 115 mm x 75 mm. The maximum load (Pmaks) was relative same while the support beam length increased are 1,52 kN; 1,53 kN; 1,53 kN and 1,55 kN. The collapse pattern on the support beam was a pure bending crack at the most significant bending moment region. The crack pattern showed the crack on the pull side of the beam in the direction of the stirrups.Semi precast slab is a combination of precast concrete which consist of the support beam and curve tile with the cast in place concrete. During the working process, support beam will support the entire load until the slab becomes solid. The study aims to identify the effect of using variations of support beam length towards deflection-load relationship, moment-curvature, crack pattern and cross-sectional dimensions caused by pure bending moments with the same maximum load. The variations of the support beam length are L = 3000 mm, L = 4000 mm, L = 5000 mm and L = 6000 mm which can affect the cross-sectional dimensions of the support beam. The method used in this study was the numerical method by using Abaqus 6.14 CAE software. Abaqus is one of the finite element analysis (FEA) programs to model and analysis the elements of the structure. The loading applied was an axial load which has increased until the support beam failed. The numerical analysis results are the increase of cross section dimension as the increasing of support beam length. The cross-sectional dimension are 100 mm x 60 mm; 110 mm x 65 mm; 110 mm x 70 mm; and 115 mm x 75 mm. The maximum load (Pmaks) was relative same while the support beam length increased are 1,52 kN; 1,53 kN; 1,53 kN and 1,55 kN. The collapse pattern on the support beam was a pure bending crack at the most significant bending moment region. The crack pattern showed the crack on the pull side of the beam in the direction of the stirrups.

Revisiting the Basis for Hip Fracture Prediction Through Bone Mineral Density Scans: Large Potential Errors and Improved Methods

2020 ◽  
Vol 3 (3) ◽  
Author(s):  
W. P. Munsell, Jr.
Keyword(s):  
Bone Mineral Density ◽  
Hip Fracture ◽  
Cross Section ◽  
Bone Mineral ◽  
Moment Of Inertia ◽  
Mineral Density ◽  
Element Analysis ◽  
Cross Sectional ◽  
Complex Cross ◽  
The Cross

Abstract Researchers have attempted to evaluate the likelihood of hip fracture as a function of an engineering concept called the moment of inertia, as applied to the cross-sectional area of hip bones. While the premise is sound, the results have been disappointing. Although several authors have acknowledged that errors may arise in the current methods investigators employ to determine the cross section moment of inertia (CSMI), none have looked critically at the sources, or even the magnitude, of those errors. This paper evaluates the nature of the error that can be introduced by the use of one-dimensional bone mineral density scans to estimate the CSMI and quantifies its impact on predictive calculations. In addition, this paper presents an improved method for approximating the mechanical section properties of highly complex cross sections. The factors affecting the accuracy of the proposed method are tested, and its error rate is also quantified. The method employs a two-dimensional analysis of digital images of the subject cross section and does not require extensive user expertise or investment in expensive finite element analysis programs to implement. The limited file space necessary to install the required code means that standard smart phones could be used to directly evaluate the most complex cross section in the field.

scholarly journals Analytical Model of a Multi-Step Straightening Process for Linear Guideways Considering Neutral Axis Deviation

Symmetry ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 316 ◽  
Author(s):  
Yongquan Zhang ◽  
Hong Lu ◽  
He Ling ◽  
Yang Lian ◽  
Mingtian Ma
Keyword(s):  
Analytical Model ◽  
Cross Section ◽  
Predictive Accuracy ◽  
Neutral Axis ◽  
Longitudinal Stress ◽  
Linear Superposition ◽  
Element Analysis ◽  
Cross Sectional ◽  
The Cross ◽  
Sectional Shape

The cross-sectional shape of a linear guideway has been processed before the straightening process. The cross-section features influence not only the position of the neutral axis, but also the applied and residual stresses along the longitudinal direction, especially in a multi-step straightening process. This paper aims to present an analytical model based on elasto-plastic theory and three-point reverse bending theory to predict straightening stroke and longitudinal stress distribution during the multi-step straightening process of linear guideways. The deviation of the neutral axis is first analyzed considering the asymmetrical features of the cross-section. Owing to the cyclic loading during the multi-step straightening process, the longitudinal stress curves are then calculated using the linear superposition of stresses. Based on the cross-section features and the superposition of stresses, the bending moment is corrected to improve the predictive accuracy of the multi-step straightening process. Finite element analysis, as well as straightening experiments, have been performed to verify the applicability of the analytical model. The proposed approach can be implemented in the multi-step straightening process of linear guideways with similar cross-sectional shape to improve the straightening accuracy.

scholarly journals Fiber-Reinforced Magnesium Phosphate Cement-Based Nanocomposites in the Field of Bridge Structure Repair and Strengthening

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Wenwei Yang
Keyword(s):  
Mechanical Properties ◽  
Magnesium Phosphate ◽  
Control Group ◽  
Bridge Structure ◽  
Fiber Reinforced ◽  
Reinforcement Effect ◽  
Analysis Software ◽  
Element Analysis ◽  
Bridge Structures ◽  
Strength And Stiffness

Currently, fiber-reinforced magnesium phosphate cement-based nanocomposites are being used in various projects. The unique physical properties of this material allow it to bear the load together with the material in the inherent structure, and it will be better used in the field of bridge structure repair and reinforcement. The purpose of this article is to study the application of fiber-reinforced magnesium phosphate cement-based nanocomposites in the field of bridge structure repair and reinforcement. Through the use of finite element analysis software and various stress sensor materials, the mechanical properties of fiber-reinforced magnesium phosphate cement-based nanocomposites are used to analyze the mechanical properties of damaged bridges in our area after reinforcement treatment and establish a control group (using magnesium phosphate cement-based nanocomposite materials) for comparative experiments. The reinforcement effect of the bridge repair structure under different ballast conditions is studied. Studies have shown that fiber-reinforced magnesium phosphate cement-based nanocomposites can provide excellent reinforcement for damaged bridge structures. Compared to the control group, the strength and stiffness of the repaired structure were significantly improved, the strength increased by 15.7%, and the stiffness increased by 12%. The carrying capacity has also been improved compared to the previous one, from the original 120 t to 150 t.

scholarly journals Recalcitrant betas: Intraday variation in the cross‐sectional dispersion of systematic risk

2021 ◽  
Vol 12 (2) ◽  
pp. 647-682 ◽  
Author(s):  
Torben G. Andersen ◽  
Martin Thyrsgaard ◽  
Viktor Todorov
Keyword(s):  
High Frequency ◽  
Opposite Effect ◽  
Functional Limit ◽  
Cross Sectional ◽  
Macroeconomic News ◽  
Market Index ◽  
Cross Sectional Dimension ◽  
Large Panel ◽  
The Cross ◽  
Over Time

We study the temporal behavior of the cross‐sectional distribution of assets' market exposure, or betas, using a large panel of high‐frequency returns. The asymptotic setup has the sampling frequency of returns increasing to infinity, while the time span of the data remains fixed, and the cross‐sectional dimension of the panel is either fixed or increasing. We derive functional limit results for the cross‐sectional distribution of betas evolving over time. We demonstrate, for constituents of the S&P 500 market index, that the dispersion in betas is elevated at the market open and gradually declines over the trading day. This intraday pattern varies significantly over time and reacts to information shocks such as clustered earning announcements and releases of macroeconomic news. We find that earnings news increase beta dispersion while FOMC announcements have the opposite effect on market betas.

Design Innovation Size and Shape Optimization of a 1.0mm Multifunctional Forceps-Scissors Surgical Instrument

2008 ◽  
Vol 2 (1) ◽  
Author(s):  
Milton E. Aguirre ◽  
Mary Frecker
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Shape Optimization ◽  
Optimization Problems ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Element Analysis ◽  
Cross Sectional ◽  
Size And Shape ◽  
The Cross

A size and shape optimization routine is developed for a 1.0mm diameter multifunctional instrument for minimally invasive surgery. The instrument is a compliant mechanism capable of both grasping and cutting. Multifunctional instruments are expected to be beneficial in the operating room because of their ability to perform multiple surgical tasks, thereby decreasing the total number of instrument exchanges in a single procedure. With fewer instrument exchanges, the risk of inadvertent tissue trauma as well as overall surgical time and costs are reduced. The focus of this paper is to investigate the performance effects of allowing the cross-sectional area along the length of the device to vary. This investigation is accomplished by defining various cross-sectional segments in terms of parametric variables and optimizing the dimensions of the instrument to provide a sufficient opening of the forceps jaws while maintaining adequate cutting and grasping forces. Two optimization problems are considered. First, all parametric segments are set equal to one another to achieve size optimization. Second, each segment is allowed to vary independently, thereby achieving shape optimization. Large deformation finite element analysis and optimization are conducted using ANSYS®. Finally, prototypes are fabricated using wire EMD and experiments are conducted to evaluate the instrument performance. As a result of allowing the cross-sectional area to vary, i.e., conducting shape optimization, the forceps and scissors blocked forces increased by as much as 83.2% and 87%, respectively. During prototype evaluations, it is found that the finite element analysis predictions were within 10% of the measured tool performance. Therefore, for this application, it is concluded that performing shape optimization does significantly influence the performance of the instrument.

Finite Element Analysis of Wind Turbine Lifting Platform Bridge Structure

2014 ◽  
Vol 687-691 ◽  
pp. 398-401 ◽  
Author(s):  
Yu Tang ◽  
Yu Hou Wu ◽  
Ke Zhang ◽  
Jia Sun ◽  
En Wei Song
Keyword(s):  
Wind Turbine ◽  
Modal Analysis ◽  
Optimization Design ◽  
Three Dimensional ◽  
Bridge Structure ◽  
Element Analysis ◽  
Nature Frequency ◽  
New Type ◽  
Strength And Stiffness ◽  
Ansys Workbench

Designed a new type of wind turbine internal maintenance lifting platform using three-dimensional drawing software SolidWorks to establish the 3D model for the internal maintenance lifting platform. Imported platform bridge part to ANSYS Workbench static and modal analysis module; make load analysis according to the wind turbine operating environment and platform’s most dangerous operating condition and obtain the maximum stress of platform bridge structure and place and form of deformation. Obtained multiple order natural frequency and vibration mode of platform bridge structure through modal analysis. Compared with the standard, it shows that this structure satisfies the strength and stiffness requirement and will generate frequency affecting human body higher than the nature frequency. This thesis provides a theoretical foundation for designing the wind driven generator internal lifting platform and provides a reference for optimization design.

scholarly journals A Study on the Influence of the Cross-Sectional Shape of the Metal-Inserted Retainer Ring and the Pressure Distribution from the Multi-Zone Carrier Head to Increase the Wafer Yield

2020 ◽  
Vol 10 (23) ◽  
pp. 8362
Author(s):  
Joon-Yeon Park ◽  
Je-Heon Han ◽  
Changwon Kim
Keyword(s):  
Finite Element ◽  
Pressure Distribution ◽  
Model Simulation ◽  
Removal Rate ◽  
Element Model ◽  
Analysis Model ◽  
Element Analysis ◽  
Cross Sectional ◽  
The Cross ◽  
Sectional Shape

In this paper, for the purpose of increasing the wafer yield by controlling the non-uniformity of the material removal rate during the chemical mechanical polishing process, the influence of the cross-sectional shape of the metal-inserted retainer ring and the pressure distribution on the wafer and the retainer ring generated from the multi-zone carrier head are investigated. First, in order to verify the finite element analysis model, it is correlated using the test data. By using a validated finite element model, simulation studies involving several parameters are performed to reduce the irregularity in the wafer: (1) tapered bottom of the retainer ring, (2) machining round corners at the bottom of the retainer ring, (3) the changes in pressure applied to the wafer, (4) the changes in pressure applied to the retainer ring.

Boom Section's Bionic Design Based on Bamboo

2013 ◽  
Vol 385-386 ◽  
pp. 34-38 ◽  
Author(s):  
Fei Xie ◽  
Zhong Peng Zhang ◽  
Xin Li ◽  
Qiang Miao
Keyword(s):  
Cross Section ◽  
Steel Plates ◽  
Bionic Design ◽  
Element Analysis ◽  
Cross Sectional ◽  
Analysis Theory ◽  
Section Design ◽  
Design Idea ◽  
Cross Sectional Design ◽  
Strength And Stiffness

From the similar analysis theory, choose the bamboo as the bionic object for boom section design; based on the microscopic characteristics of the bionic object, the author design the boom section with the idea of multistory steel-plates. Based on ABAQUS Standard solver for finite element analysis, gets the boom’s properties on strength and stiffness. compared with the traditional cross-section, bionic boom is superior on strength. The bionic cross-sectional design idea breaks the traditional ways of crane boom design, optimization, and provides a new reference direction.

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