scholarly journals Experimental and numerical study on the screw connection strength of bamboo-oriented strand board compared with wood-oriented strand board

2021 ◽  
Vol 67 (1) ◽  
Author(s):  
Kaiting Zhang ◽  
Fuli Wang ◽  
Runmin Xu ◽  
Xinhui Fan ◽  
Bin Yan ◽  
...  
Keyword(s):  
Bending Strength ◽  
Oriented Strand Board ◽  
Numerical Study ◽  
Bending Moment ◽  
Experimental Tests ◽  
Stiffness Coefficient ◽  
The Difference ◽  
Strength And Stiffness ◽  
Von Mises ◽  
Von Mises Stresses

AbstractThe utilization of resourceful bamboo can alleviate the wood shortage problem. Bamboo-oriented strand board (BOSB) with the highest utilization of bamboo ratio and excellent mechanical properties was considered as a good engineering and furniture material. The strength of joints affects the safety of BOSB structure. This study aims to investigate the effect of screw spacing on the tensile and compressive stiffness and strength of corner joints from BOSB by experimental method combined with finite element method (FEM) compared with wood-oriented strand board (WOSB). The results showed that (1) the strength and stiffness of the corner joint was significantly affected by the screw spacing, and it affected the compressive strength and stiffness of WOSB more significantly; (2) the bending moment and stiffness coefficient of BOSB compressed joint decreased with the increase of spacing, while that of tensile joint increased first and then decreased, and it reached the maximum value, when the spacing was 48 mm; (3) compared with WOSB joint, BOSB joint had higher strength and stiffness, and the failure of the joint was due to the yielding of self-drilling screws. This was also verified by numerical analysis results; (4) the bending moment of BOSB joints was about 2.5 times that of WOSB joints, while the difference between stiffness coefficient was small; (5) the elastic deformations resulted from experimental tests and FEM are similar. It was shown that when the screw spacing is 48 mm, the Von Mises stresses on the BOSB joint were smaller, and the bending strength and stiffness were larger, which was the most suitable screw spacing.

State of Stress of Castellated Beams with Circular Apertures under Distributed Load and Pure Bending

2019 ◽  
Vol 974 ◽  
pp. 521-528
Author(s):  
Alexej I. Pritykin
Keyword(s):  
Empirical Relation ◽  
Bending Moment ◽  
Empirical Dependence ◽  
Ansys Software ◽  
Pure Bending ◽  
Equivalent Stresses ◽  
Distributed Load ◽  
State Of Stress ◽  
Von Mises ◽  
Von Mises Stresses

The regularities of stress distribution in perforated beams with circular apertures under distributed load and pure bending. Such beams are made of different materials: carbon fiber is used in aircraft for these purposes, and steel is used in construction. Beams with different perforation parameters were considered and an empirical relation was obtained for equivalent von Mises stresses in castellated beams near the apertures’ outlines based on the analysis of FEM calculations. In this paper, beams made of C345 steel were considered. It is established that the maximum values ​​of equivalent stresses near apertures under different loading types vary along the beam length in proportion to the values ​​of the bending moment. The values ​​of stress concentration coefficients for the pure bending are determined depending on the perforation parameters. The acceptability of the obtained empirical dependencies for equivalent stresses was verified using the FEM calculations based on the ANSYS software package. There is a good correlation between the results of FEM calculations and empirical dependence.

scholarly journals Strength and stiffness analyses of standard and double mortise and tenon joints

BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 8249-8267
Author(s):  
Seid Hajdarevic ◽  
Murco Obucina ◽  
Elmedin Mesic ◽  
Sandra Martinovic
Keyword(s):  
Bending Moment ◽  
Von Mises Stress ◽  
Elastic Model ◽  
Proportional Limit ◽  
Linear Elastic ◽  
Mortise And Tenon ◽  
Strength And Stiffness ◽  
Experimental Values ◽  
Maximal Moment ◽  
Von Mises

This paper investigated the effect of the tenon length on the strength and stiffness of the standard mortise and tenon joints, as well of the double mortise and tenon joints, that were bonded by poly(vinyl acetate) (PVAc) and polyurethane (PU) glues. The strength was analyzed by measuring applied load and by calculating ultimate bending moment and bending moment at the proportional limit. Stiffness was evaluated by measuring displacement and by calculating the ratio of applied force and displacement along the force line. The results were compared with the data obtained by the simplified static expressions and numerical calculation of the orthotropic linear-elastic model. The results indicated that increasing tenon length increased the maximal moment and proportional moment of the both investigated joints types. The analytically calculated moments were increased more than the experimental values for both joint types, and they had generally lower values than the proportional moments for the standard tenon joints, as opposed to the double tenon joints. The Von Mises stress distribution showed characteristic zones of the maximum and increased stress values. These likewise were monitored in analytical calculations. The procedures could be successfully used to achieve approximate data of properties of loaded joints.

IDENTIFICATION OF GRANULAR SOILS STRENGTH AND STIFFNESS PARAMETERS BY MATCHING FINITE ELEMENT RESULTS TO PMT DATA

2014 ◽  
Vol 11 (02) ◽  
pp. 1342001 ◽  
Author(s):  
Y. ABED ◽  
R. BAHAR ◽  
J.-C. DUPLA ◽  
DJ. AMAR BOUZID
Keyword(s):  
Finite Element ◽  
Experimental Tests ◽  
Loading Path ◽  
Soil Parameters ◽  
Model Parameters ◽  
Expansion Curve ◽  
The Difference ◽  
Strength And Stiffness ◽  
Analytical Expressions

This paper describes an efficient methodology for the identification of soil parameters using the combination of the finite element method and the in situ pressuremeter test (PMT). The objective of the procedure applied here is to identify the parameters of generalized Prager model associated with the Drucker and Prager failure criterion from a pressuremeter expansion curve. The approach consists of minimizing the function representing the difference between the experimental curve and the curve obtained by integrating the model along the loading path in the in situ testing. First, both analytical expressions governing the problem of cavity expansion and those related to the finite element modeling are given in detail. Then, a Fortran computer program called "Press-Sim" along with the solution strategy are described and clearly explained. The influence of some model parameters as well as the probe geometry on the computed pressuremeter curves is examined. The paper finishes by presenting some identification examples drawn from real experimental tests for which the targeted parameters are compared with those of other experimental procedures. Results of comparison show a very good agreement.

Numerical Study on Concentric Braced X Frames under Monotonic and Cyclic Loads

2018 ◽  
Vol 763 ◽  
pp. 633-641 ◽  
Author(s):  
Beatrice Faggiano ◽  
Antonio Formisano ◽  
Generoso Vaiano ◽  
Federico M. Mazzolani
Keyword(s):  
Numerical Study ◽  
Elastic Field ◽  
Seismic Energy ◽  
Experimental Tests ◽  
Cyclic Loads ◽  
Braced Frames ◽  
Structural Behaviour ◽  
Factors Affecting ◽  
Strength And Stiffness ◽  
Set Up

Concentric Braced Frames (CBF) are designed for dissipating the seismic energy mainly through plastic deformations of diagonals in tension, while beams and columns, designed on the basis of the hierarchy resistance criterion, should resist the design loads in elastic field without undergoing buckling and yielding phenomena. For such structural systems there are still some uncertainties on the performances under cyclic loadings, due to the degradation of the strength and stiffness under tension for the occurrence of instability problems in compression. The current paper deepens such key issues, presenting the numerical simulation of some literature experimental tests conducted on CBX frames subjected to monotonic and cyclic loads both in presence and in absence of vertical loads. The refined FE structural models of the study systems are developed through the software ABAQUS v6.13-1. The models set up have provided a very good replication of both monotonic and hysteretic behaviours in terms of strength, stiffness, ductility and energy dissipation. They are powerful analysis instruments to perform parametric studies, aiming at detecting the main factors affecting the cyclic structural behaviour, thus leading towards appropriate design criteria.

Bending properties of stainless steel dynamic compression plates and limited contact dynamic compression plates

2001 ◽  
Vol 14 (02) ◽  
pp. 64-68 ◽  
Author(s):  
C. M. Hill ◽  
T. Kageyama ◽  
M. G. Conzemius ◽  
G. K. Smith ◽  
F. M. Little
Keyword(s):  
Stainless Steel ◽  
Fracture Healing ◽  
Bending Strength ◽  
Dynamic Compression ◽  
Bending Stiffness ◽  
Four Point Bending ◽  
Plate Size ◽  
Equivalent Bending Stiffness ◽  
The Difference ◽  
Strength And Stiffness

SummaryThe equivalent bending stiffness and bending strength of the stainless steel DCP and stainless steel LC-DCP were compared. Three plates, of each size, were tested destructively in ‘four point bending’. All of the LC-DCP were significantly less stiff and less strong than the comparable size DCP, with the exception of the 4.5 mm narrow LC-DCP which was significantly stronger and more stiff than the 4.5 mm narrow DCP (p <.01). The design advantages of the LC-DCP are ease and versatility of plate application and improved cortical blood flow which one assumes promotes fracture healing. Also, the lower recorded stiffness of the LC-DCP may be advantageous in that it decreases the stress protection of the plated bone. Since optimal strength and stiffness of bone plates are currently unknown, the clinical relevance of the decreased strength and stiffness of the LC-DCP has yet to be determined.Stainless steel LC-DCP and DCP of various sizes were tested in four point bending to ascertain equivalent bending stiffness and bending strength of each type of plate. The LC-DCP were consistently less stiff and strong than their DCP counterparts (p <.01) with the exception of the 4.5 mm Narrow LC-DCP which was stronger and more stiff than the 4.5 mm Narrow DCP. In general, as plate size increased. the difference between the two plate designs decreased. If it can be shown that there is not any detrimental effect on fracture healing, the design features of the LC-DCP make it a desirable choice for most fracture applications.

Experimental and Numerical Study of Performance Behavior of Triangular Seal Under High Hydraulic Pressure

2018 ◽  
Vol 140 (2) ◽  
Author(s):  
Bruno R. Mose ◽  
Hyun-Seok Lim ◽  
Dong-Kil Shin
Keyword(s):  
Numerical Simulation ◽  
Cross Section ◽  
Numerical Study ◽  
Hydraulic Pressure ◽  
Element Analysis ◽  
Rocket Propulsion ◽  
Fringe Patterns ◽  
Von Mises ◽  
Von Mises Stresses ◽  
Performance Behavior

In this paper, a seal with triangular cross section was proposed and its performance behavior under compression and various hydraulic pressures was analyzed through experimental and numerical methods. The seal was designed to have a 90 deg corner located near the extrusion gap while hydraulic pressure was applied at an inclination. With this design, it was found that even at hydraulic pressures of up to 18 MPa, the seal offered good fluid tight sealing capabilities without indications of extrusion failures. Such high pressure offers new possibilities for successful application of the seal in aircraft and rocket propulsion equipment. Moreover, the resistance of the seal against leakages was assured because measured contact stresses were greater than applied pressures. A numerical simulation through finite element analysis (FEA) showed that tilting of the delta ring even at angles of ±5 deg did not have any effect on the Von Mises stresses. The FEA results also demonstrated that the deformations and fringe patterns of delta ring were similar to the experimental results.

A comparative numerical study to compute ocular injury in boxing

2019 ◽  
Vol 234 (2) ◽  
pp. 125-135
Author(s):  
Reza Razaghi ◽  
Hasan Biglari
Keyword(s):  
Finite Element ◽  
Optic Nerve ◽  
Numerical Study ◽  
Vitreous Body ◽  
Ocular Injury ◽  
Eye Injuries ◽  
Ocular Injuries ◽  
Von Mises ◽  
Von Mises Stresses ◽  
The Impact

Sport is responsible for between 25% and 40% of all eye injuries. Trauma is integrated to the nature of the sport, especially boxing, which is considered a high-risk sport for ocular injuries. Boxing not only brings about injury to the external side of the eye, but in nearly one third of cases, the intraocular components of the eye are also damaged, followed by serious visual acuity complications. However, so far there is a paucity of knowledge on the ocular injury as a result of a strong hook to the face during boxing. This study was, therefore, aimed to perform a dynamic finite element simulation to calculate the stresses and deformations to the components of the eye (i.e. the cornea, aqueous body, iris, ciliary body, vitreous body, sclera, retina, and optic nerve) as a consequence of a hook to the zygomatic and frontal skull bones of a boxer. To do that, well-verified finite element models of the human skull, eye, and punch developed by the current authors were employed to simulate the traumatic model of the skull. The resulting von Mises stresses and deformations in each component of the eye were calculated and compared. The results revealed higher stresses in the components of the eye as a result of a frontal impact compared to that of the zygomatic one. The concentration of the von Mises stresses in the eye components was mostly located in the lateral circumference of the globe. Regardless of the impact sites, the muscle experienced severe damage while the cornea, as the most anterior, and optic nerve, as the most posterior components of the eye, stayed safe with trivial amounts of stress and deformation. These results have implications not only for understanding the possible ocular injuries from a hook but also for providing comprehensive information to medical experts regarding the types of ocular injuries which may occur during boxing.

scholarly journals Experimental Analysis of Pretensioned CLT-Glulam T-Section Beams

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
J. Estévez-Cimadevila ◽  
F. Suárez-Riestra ◽  
D. Otero-Chans ◽  
E. Martín-Gutiérrez
Keyword(s):  
Picea Abies ◽  
Quercus Robur ◽  
Bending Strength ◽  
Load Capacity ◽  
The Other ◽  
Unbonded Tendons ◽  
Bending Behavior ◽  
The Difference ◽  
Strength And Stiffness ◽  
Moduli Of Elasticity

The bending behavior of T-section beams composed of a glulam web and an upper cross-laminated timber flange was studied. The influence of two fundamental factors on the bending strength and stiffness was considered: the wood species used for the webs and pretensioning with unbonded tendons. Sixteen specimens with a 9 m span were tested until failure: eight of them were nontensioned (4 Picea abies webs and 4 Quercus robur webs) and the other eight were pretensioned using threaded bars with 20 mm diameter anchored in plates fixed at the ends of the specimens (4 Picea abies webs and 4 Quercus robur webs). Pretensioning with unbonded tendons showed a clear improvement in the load capacity of the specimens with Picea abies webs, while the difference was not significant for the specimens with Quercus robur webs. Considering deflection, pretensioning gave the advantage of an initial precamber but also generated slight variations in the stiffness as a result of increasing the portion of the section that was in compression. The variation in the stiffness depended on the relation between the compressive and tensile moduli of elasticity parallel to the grain, and its influence on the deflection was analyzed using a finite element method.

scholarly journals Research: Design and Analysis of a Low-Stiffness Porous Hip Stem

2017 ◽  
Vol 51 (6) ◽  
pp. 474-482
Author(s):  
Ibrahim Eldesouky ◽  
Hassan El-Hofy ◽  
Ola Harrysson
Keyword(s):  
Mechanical Properties ◽  
Bone Ingrowth ◽  
Numerical Study ◽  
Stress Shielding ◽  
Tissue Reaction ◽  
Adverse Tissue Reaction ◽  
Von Mises ◽  
Tissue Reactions ◽  
Von Mises Stresses ◽  
Minimum Safety Factor

Abstract Two major problems are associated with total hip replacement: 1) stress shielding and 2) the adverse tissue reaction to certain elements of the implant material. In this regard, a porous implant provides lower stiffness and vacancies for bone ingrowth, making it more suitable for the human bone compared with a solid stem. Moreover, second-generation titanium biomedical alloys, such as TNZT (Ti35Nb7Zr5Ta) and TMZF (Ti12Mo6Zr2Fe), have been introduced to prevent the adverse tissue reactions related to aluminum and vanadium elements of the popular Ti6Al4V alloy. In the current work, an analysis was performed based on uniaxial compression testing of cubic Ti6Al4V structures of different porosities to predict the governing equations that relate the relative density of the structure to the mechanical properties of the structure according to the Gibson-Ashby model. A numerical study was conducted to evaluate the change in stress distribution obtained by incorporating the new titanium alloys in porous hip stem implants. Implants modeled with the mechanical properties of TNZT and TMZF showed a minimum safety factor of 1.69 and 3.02, respectively, with respect to the yield strength. The results demonstrated an increase in the equivalent von Mises stresses and maximum principal elastic strain up to 7% and 15%, respectively, compared with the porous Ti6Al4V implant and up to 108% and 156%, respectively, compared with the solid Ti6Al4V implant.

scholarly journals Von Mises stresses on Mushroom-loop archwires for incisor retraction: a numerical study

2020 ◽  
Vol 25 (4) ◽  
pp. 44-50
Author(s):  
Marcelo do Amaral Ferreira ◽  
Fábio Rodrigo Mandello Rodrigues ◽  
Marco Antônio Luersen ◽  
Paulo César Borges ◽  
Ravindra Nanda ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Cross Section ◽  
Small Area ◽  
Numerical Study ◽  
Linear Analysis ◽  
Finite Element Code ◽  
Incisor Retraction ◽  
Von Mises ◽  
Von Mises Stresses ◽  
Ansys Workbench

ABSTRACT Objective: To perform a numerical simulation using FEM to study the von Mises stresses on Mushroom archwires. Methods: Mushroom archwires made of titanium-molybdenum alloy with 0.017 x 0.025-in cross-section were used in this study. A YS of 1240 MPa and a Young’s modulus of 69 GPa were adopted. The archwire was modeled in Autodesk Inventor software and its behavior was simulated using the finite element code Ansys Workbench (Swanson Analysis Systems, Houston, Pennsylvania, USA). A large displacement simulation was used for non-linear analysis. The archwires were deformed in their extremities with 0° and 45°, and activated by their vertical extremities separated at 4.0 or 5.0 mm. Results: Tensions revealed a maximum of 1158 MPa at the whole part of the loop at 5.0mm of activation, except in a very small area situated at the top of the loop, in which a maximum of 1324 Mpa was found. Conclusions: Mushroom loops are capable to produce tension levels in an elastic range and could be safely activated up to 5.0mm.

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