scholarly journals Monotonic Response of Exposed Base Plates of Columns: Numerical Study and a New Design Method

Metals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 396
Author(s):  
Héctor Díaz ◽  
Eduardo Nuñez ◽  
Claudio Oyarzo-Vera
Keyword(s):  
Numerical Study ◽  
Design Method ◽  
Numerical Models ◽  
Failure Mechanisms ◽  
Plate Thickness ◽  
Base Plate ◽  
Traditional Design ◽  
Current Design ◽  
Bending Loads ◽  
Base Plates

This paper describes a numerical study of the behavior of exposed base plates of columns under the action of axial and bending loads. The aim of this research is to evaluate numerically the failure mechanisms on stiffened and non-stiffened base plates and propose a new design method. The effects of base plate thickness, location of anchor rods, location of stiffeners and tensile strength of anchor rods were considered in the analysis. Sixteen finite elements simulations were performed considering different combinations of the above mentioned parameters. The results show a fragile response in the base plates when high resistance anchor rods are used. The anchor rods worked as fuse elements in base plates with a large thickness or many stiffeners. Additionally, the models with anchor bars located outside of the column flanges showed lower flexural strength and rotational stiffness compared to the models with anchor rods located between column flanges. The simulations showed that the base plate strength was determined by the simultaneous failure mechanisms of two or more components, different to what is stated in current design guides. Finally, the new method is suitable to design base plates with stiffened and not stiffened configurations, which unlike traditional design methods, show a good adjustment with numerical models.

scholarly journals ТЕОРЕТИЧНЕ ДОСЛІДЖЕННЯ НАПРУЖЕНО-ДЕФОРМОВАНОГО СТАНУ БАЗОВИХ ПЛИТ УЗРП-16

2020 ◽  
pp. 151-164
Author(s):  
Є. А. Фролов ◽  
Б. О. Коробко ◽  
С. В. Попов
Keyword(s):  
Strain State ◽  
Structural Parameters ◽  
Plate Thickness ◽  
Bending Moment ◽  
Base Plate ◽  
Plate Surface ◽  
Stress Strain ◽  
Stress Strain State ◽  
Study Results ◽  
Base Plates

Theoretical studies of the stress-strain state of base plates, which are the base of the UZRP-16 universal collapsible machines have been done. These machines are used for welding works in machine building industry. The finite element method was applied to solve the problems. Nature of influence of strength and structural parameters on the base plate stress-strain state in operation has been determined, namely: the relations between displacements and stresses arising in the base plates and the bending moment magnitudes have been recorded; the stress-strain state pattern of the base plates has been obtained depending on the place of bending moment application; influence of the conditions for bearing and fastening the plates on their stress-strain state has been investigated; influence of the plate geometric parameters on stress and displacement has been studied; The stress-material and displacement-material relations have been obtained for the plates. Based on the theoretical study results of the base plate stress-strain state, the following have been obtained: stress plots and patterns of deformed surfaces, which are symmetrical with respect to the plate central axes; maximum values of normal and tangential stress components arising in the field of bending moment application; stress on the rectangular base plate surface is 2.1 times higher than the stress on square plate surface under the same conditions of bearing and loading; stresses acting on the plate surfaces and being tensile stresses within the range of 10 to 70 MPa. It was found that the square shape of the plates, according to the stress state, is predominant in relation to the rectangular shape. The optimal condition for bearing is fixing the plates at nine points. For the first time, graphs were drawn for choosing the base plate thickness under action of various operational loads.

scholarly journals Numerical Study on the Effect of Concrete Grade on the CFT Circular Column’s Behavior under Axial Load

2019 ◽  
Vol 5 (11) ◽  
pp. 2359-2376
Author(s):  
Baitollah Badarloo ◽  
Faezeh Jafari
Keyword(s):  
Finite Element ◽  
Numerical Study ◽  
Design Method ◽  
Load Capacity ◽  
Pushover Analysis ◽  
Safety Level ◽  
Finite Element Software ◽  
Current Design ◽  
Load Pattern ◽  
Cft Column

Concrete-filled tubular (CFT) column improves the structure properties under different load pattern, so that it should be designed under two main load patterns (static and cyclic load) using current design method such as Finite Element Method (FEM) and analytical method (guideline equation). In this research, a CFT column with specific dimensions is modeled by using ABAQUS finite element software; the target of this study is to conduct a pushover analysis and also a hysteresis analysis under cyclic loading. Then, the concrete grade and percentage of column reinforcement were altered using the FEM, and eventually, compared with the results of analytical equations to measure the safety level of analytical equations. For this purpose, the CFT columns with C20, 30, 40 & 50 concrete cores were modeled with and without reinforcement, and the effect of concrete grade on the capacity of column was studied. In addition, MATLAB software was used to obtain beta index and load capacity design for the CFT column. The results demonstrated that the columns designed in accordance with the AISC have a good performance under the cyclic and static loading. The safety level of design equations ranged between 3 and 5, and the columns could resist higher loads (about 2.5-3.5 times) through the design by ABAQUS.

Damage sequence of honeycomb sandwich panels under bending loading: Experimental and numerical investigation

2019 ◽  
Vol 39 (5-6) ◽  
pp. 175-192
Author(s):  
SA Medina ◽  
JM Meza ◽  
Luiz F Kawashita
Keyword(s):  
Numerical Models ◽  
Experimental Testing ◽  
Failure Mechanisms ◽  
Sandwich Panels ◽  
Component Level ◽  
Plane Shear ◽  
Damage Mechanisms ◽  
Bending Loads ◽  
Observed Damage ◽  
Structural Levels

This work presents a numerical modelling study on the bending response and failure mechanisms of aramid skin/aluminium honeycomb core sandwich panels under quasi-static bending loads. These composite sandwich panels are widely used in aerospace and automotive industries, in spite of the limitations for their use in complex structures, such as the extensive experimental testing needed at the component and full-size structural levels, which are expensive and time-consuming. The aim of this study was to capture the initiation of different failure mechanisms and their multiple interactions, which are known to strongly influence the observed microscopic behaviour of the material. Furthermore, a series of detailed Finite Element models were built and analysed in an attempt to replicate the complex damage mechanisms observed experimentally. The results show good correlation between numerical models and experimental results, both in terms of the global load–displacement behaviour and the observed damage mechanisms, including skin in-plane shear and compression damage, intralaminar fracture, delamination within the skin and core crushing. No debonding between the core and the skins was evidenced. It is proposed that this modelling approach can become a feasible alternative to component-level experimental testing when designing complex sandwich structures.

scholarly journals Investigation of the Structural Strength of Existing Blast Walls in Well-Test Areas on Drillships

2020 ◽  
Vol 8 (8) ◽  
pp. 583
Author(s):  
Byeongkwon Jung ◽  
Jeong Hwan Kim ◽  
Jung Kwan Seo
Keyword(s):  
Risk Analysis ◽  
Structural Strength ◽  
Design Method ◽  
Plate Thickness ◽  
Offshore Structures ◽  
Well Test ◽  
Current Design ◽  
Fire And Explosion ◽  
Explosion Accidents ◽  
Explosion Risk

Blast walls are installed on the topside of offshore structures to reduce the damage from fire and explosion accidents. The blast walls on production platforms such as floating production storage, offloading, and floating production units undergo fire and explosion risk analysis, but information about blast walls on the well-test area of drillship topsides is insufficient even though well tests are performed 30 to 45 times per year. Moreover, current industrial practices of design method are used as simplified elastically design approaches. Therefore, this study investigates the strength characteristic of blast wall on drillship based on the blast load profile from fire and explosion risk analysis results, as well as the ability of the current design scantling of the blast wall to endure the blast pressure during the well test. The maximum plastic strain of the FE results occurs at the bottom connection between the vertical girder and the blast wall plate. Based on the results, several alternative design applications are suggested to reduce the fabrication cost of a blast wall such as differences of stiffened plated structure and corrugated panels, possibility of changing material (mild steel), and reduced plate thickness for application in current industrial practices.

scholarly journals Evolution of Meniscal Biomechanical Properties with Growth: An Experimental and Numerical Study

2021 ◽  
Vol 8 (5) ◽  
pp. 70
Author(s):  
Marco Ferroni ◽  
Beatrice Belgio ◽  
Giuseppe M. Peretti ◽  
Alessia Di Giancamillo ◽  
Federica Boschetti
Keyword(s):  
Mechanical Properties ◽  
Stress Relaxation ◽  
Developmental Stage ◽  
Mechanical Response ◽  
Numerical Study ◽  
Numerical Models ◽  
Mechanical Stimulus ◽  
Specific Response ◽  
Mechanical Parameters ◽  
Biochemical Analyses

The menisci of the knee are complex fibro-cartilaginous tissues that play important roles in load bearing, shock absorption, joint lubrication, and stabilization. The objective of this study was to evaluate the interaction between the different meniscal tissue components (i.e., the solid matrix constituents and the fluid phase) and the mechanical response according to the developmental stage of the tissue. Menisci derived from partially and fully developed pigs were analyzed. We carried out biochemical analyses to quantify glycosaminoglycan (GAG) and DNA content according to the developmental stage. These values were related to tissue mechanical properties that were measured in vitro by performing compression and tension tests on meniscal specimens. Both compression and tension protocols consisted of multi-ramp stress–relaxation tests comprised of increasing strains followed by stress–relaxation to equilibrium. To better understand the mechanical response to different directions of mechanical stimulus and to relate it to the tissue structural composition and development, we performed numerical simulations that implemented different constitutive models (poro-elasticity, viscoelasticity, transversal isotropy, or combinations of the above) using the commercial software COMSOL Multiphysics. The numerical models also allowed us to determine several mechanical parameters that cannot be directly measured by experimental tests. The results of our investigation showed that the meniscus is a non-linear, anisotropic, non-homogeneous material: mechanical parameters increase with strain, depend on the direction of load, and vary among regions (anterior, central, and posterior). Preliminary numerical results showed the predominant role of the different tissue components depending on the mechanical stimulus. The outcomes of biochemical analyses related to mechanical properties confirmed the findings of the numerical models, suggesting a specific response of meniscal cells to the regional mechanical stimuli in the knee joint. During maturation, the increase in compressive moduli could be explained by cell differentiation from fibroblasts to metabolically active chondrocytes, as indicated by the found increase in GAG/DNA ratio. The changes of tensile mechanical response during development could be related to collagen II accumulation during growth. This study provides new information on the changes of tissue structural components during maturation and the relationship between tissue composition and mechanical response.

Seismic Risk Mitigation of Historical Masonry Towers by Means of Prestressing Devices

2010 ◽  
Vol 133-134 ◽  
pp. 843-848 ◽  
Author(s):  
Adolfo Preciado Quiroz ◽  
Silvio T. Sperbeck ◽  
Harald Budelmann ◽  
Gianni Bartoli ◽  
Elham Bazrafshan
Keyword(s):  
Seismic Risk ◽  
Seismic Vulnerability ◽  
Risk Mitigation ◽  
Numerical Models ◽  
Failure Mechanisms ◽  
Masonry Towers ◽  
Seismic Risk Mitigation ◽  
Historical Masonry ◽  
Observed Damage ◽  
And Behavior

This work presents the investigation of the efficiency of different prestressing devices as a rehabilitation measure for the seismic risk mitigation of historical masonry towers. As a first phase, the seismic vulnerability of theoretical masonry towers was assessed by means of numerical models validated with information from the literature, observed damage and behavior of these structures due to passed earthquakes (crack pattern and failure mechanisms), and mainly taking into account the engineering experience. Afterwards, the validated models were rehabilitated with different prestressing devices; analyzing the results and concluding which device or the combination of them improved in a better way the seismic performance of the masonry towers. Finally, the methodology will be applied in two historical masonry towers located in seismic areas; the medieval tower “Torre Grossa” of San Gimignano, Italy, and one of the bell towers of the Cathedral of Colima, Mexico.

Finite Element Analysis and Optimization of Long-Span Gantry NC Machining Center Structure

2011 ◽  
Vol 346 ◽  
pp. 379-384
Author(s):  
Shu Bo Xu ◽  
Yang Xi ◽  
Cai Nian Jing ◽  
Ke Ke Sun
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Design Method ◽  
Dynamic Performance ◽  
Plate Thickness ◽  
Element Model ◽  
Wall Structure ◽  
Characteristic Analysis ◽  
Element Analysis ◽  
Dynamic Performance Analysis

The use of finite element theory and modal analysis theory, the structure of the machine static and dynamic performance analysis and prediction using optimal design method for optimization, the new machine to improve job performance, improve processing accuracy, shorten the development cycle and enhance the competitiveness of products is very important. Selected for three-dimensional CAD modeling software-UG NX4.0 and finite element analysis software-ANSYS to set up the structure of the beam finite element model, and then post on the overall structure of the static and dynamic characteristic analysis, on the basis of optimized static and dynamic performance is more superior double wall structure of the beam. And by changing the wall thickness and the thickness of the inner wall, as well as the reinforcement plate thickness overall sensitivity analysis shows that changes in these three parameters on the dynamic characteristics of post impact. Application of topology optimization methods, determine the optimal structure of the beam ultimately.

Factored axial compressive resistance of schifflerized angles

1991 ◽  
Vol 18 (6) ◽  
pp. 926-932 ◽  
Author(s):  
Seshu Madhava Rao Adluri ◽  
Murty K. S. Madugula
Keyword(s):  
Key Words ◽  
Design Method ◽  
Design Criteria ◽  
Design Practice ◽  
Buckling Mode ◽  
Flexural Buckling ◽  
Mode Of Failure ◽  
Current Design ◽  
Similarities And Differences ◽  
Compressive Resistance

The concept of schifflerization of 90° equal-leg angle is presented and its application in triangular-base latticed steel towers is explained. The similarities and differences between schifflerized angles and regular 90° angles are discussed. The current design practice for schifflerized angles is reviewed and its limitation is highlighted. A design method which includes the effect of the torsional-flexural buckling mode of failure is proposed. For ready use of designers, the factored axial compressive resistances of schifflerized angles are tabulated for both the present and proposed design methods. Key words: buckling, compressive resistance, design criteria, schifflerized angles, stability, standards, steel, struts, towers, guyed towers.

The Analysis on Manufacture Cost of Fire Robot Based on Modular Design

2014 ◽  
Vol 716-717 ◽  
pp. 1518-1521
Author(s):  
Shu Fang ◽  
Yan Xu ◽  
Fei Dong
Keyword(s):  
Modular Design ◽  
Design Method ◽  
Working Environment ◽  
Activity Based Costing ◽  
Traditional Design ◽  
Different Types ◽  
Function Modules ◽  
Flexible Manufacture ◽  
Technical Platform ◽  
General Technical

The manufacture of fire robot has characteristics such as different types and piece production, and flexible manufacture and cost control of the fire robot must be considered due to these characteristics. In this paper, the similarity of fire robot’s working environment was analyzed, The demand of chassis’s adaptability and the method using general technical platform were discussed with the thinking of modular design, and new series fire robots which composed of the general platform and different function modules were proposed, and the manufacture cost of traditional design method and modular design method were compared in using the activity-based costing method, and under the new design method the manufacture cost were decreased extremely.

Numerical Study of Corrugated Metal Panels Subjected to Windborne Debris Impacts

2014 ◽  
Vol 626 ◽  
pp. 109-114
Author(s):  
Wen Su Chen ◽  
Hong Hao ◽  
Hao Du
Keyword(s):  
Extreme Event ◽  
Numerical Study ◽  
Numerical Models ◽  
Economic Loss ◽  
Wind Loading ◽  
Windborne Debris ◽  
Study Laboratory ◽  
The Impact ◽  
Metal Panels ◽  
Corrugated Metal

Hurricane, typhoon and cyclone take place more and more often around the world with changing climate. Such nature disasters cause tremendous economic loss and casualty. Various kinds of windborne debris such as compact-like, plate-like and rod-like objects driven by hurricane usually imposes localized impact loading on the structure envelopes such as cladding, wall or roof, etc. The dominant opening in the envelope might cause serious damage to the structures, even collapse. To withstand the impact of such extreme event, the requirements on panel capacity to resist windborne debris impact has been presented in the Australian Wind Loading Code (2011) [1]. Corrugated metal panels are widely used as building envelop. In a previous study, laboratory tests have been carried out to investigate the performance of corrugated metal panels subjected to a 4kg wooden projectile by considering various impact locations, impact velocities and boundary conditions. In this study, numerical models were developed to simulate the responses of the corrugated metal panels subjected to wooden debris impacts by using commercial software LS-DYNA. The predicted data from the numerical simulations were compared with the experimental results. The validated numerical model can be used to conduct intensive numerical simulation to study the failure probabilities of corrugated structural panels subjected to windborne debris impacts.

Sign in / Sign up

Export Citation Format

Share Document