scholarly journals Structural design and mechanical properties analysis of bamboo-wood cross-laminated timber

BioResources ◽  
2020 ◽  
Vol 15 (3) ◽  
pp. 5417-5432
Author(s):  
Chao Li ◽  
Xilong Wang ◽  
Yizhuo Zhang

To explore the overall mechanical properties of bamboo-wood composite cross-laminated timber (BCLT), a simulation model of BCLT mechanical behavior based on the solid element was established using the finite element software ABAQUS. The actual four-point bending experiment was compared and analyzed with the finite element numerical simulation. The total curve error coefficient of the BCLT specimen at 18-mm displacement was 0.2988 while the interval was 0.5 mm. The error coefficient was 0.0178 when the maximum load was reached, and the minimum error coefficient was 0.0015 at 12 mm of displacement. Analysis of the influence of material parameters, meshing density, and material arrangement on the final stress distribution indicate that the difference in the elastic parameters of the material greatly influence the final stress distribution, and the arrangement and combination of materials also have an effect on the overall mechanical properties of the BCLT board. The combination CLT1-2-1 (i.e., the upper and lower layers of the bamboo are Arrangement 1 and the hemlock is Arrangement 2) have a maximum load of 57682 Ν and a maximum stress of 103.9 MPa.

2013 ◽  
Vol 438-439 ◽  
pp. 987-990 ◽  
Author(s):  
Xiao Hui Xue ◽  
Zhi Jie Sun ◽  
Zhong Ming Su ◽  
Fei Song

For a comprehensive analysis of the mechanical properties of compound-umbrella arch in the unsymmetrically loaded tunnel entrance, we focus on the force characteristics to optimize the structure of composite umbrella arch, and improve its economic efficiency. The stresses on the bottom of pile, the pile and the steel arch were monitored, and analyzed by the finite element software. The results show that, on the bias terrain, the stress of the pile bottom is nonuniform with uneven settlement. The stress distribution is very complex, where the tensile stress appears on the pile bottom, the compressive stress takes place on the arch foot and the vault, which is not good to the stability of the overall umbrella arch. As both sides of the umbrella arch bear a large different force, the piles on both sides of the umbrella arch subject to large bending moment and axial force, which improve the stability of the tunnel entrance.


Symmetry ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 39
Author(s):  
Łukasz Warguła ◽  
Dominik Wojtkowiak ◽  
Mateusz Kukla ◽  
Krzysztof Talaśka

This article presents the results of experimental research on the mechanical properties of pine wood (Pinus L. Sp. Pl. 1000. 1753). In the course of the research process, stress-strain curves were determined for cases of tensile, compression and shear of standardized shapes samples. The collected data set was used to determine several material constants such as: modulus of elasticity, shear modulus or yield point. The aim of the research was to determine the material properties necessary to develop the model used in the finite element analysis (FEM), which demonstrates the symmetrical nature of the stress distribution in the sample. This model will be used to analyze the process of grinding wood base materials in terms of the peak cutting force estimation and the tool geometry influence determination. The main purpose of the developed model will be to determine the maximum stress value necessary to estimate the destructive force for the tested wood sample. The tests were carried out for timber of around 8.74% and 19.9% moisture content (MC). Significant differences were found between the mechanical properties of wood depending on moisture content and the direction of the applied force depending on the arrangement of wood fibers. Unlike other studies in the literature, this one relates to all three stress states (tensile, compression and shear) in all significant directions (anatomical). To verify the usability of the determined mechanical parameters of wood, all three strength tests (tensile, compression and shear) were mapped in the FEM analysis. The accuracy of the model in determining the maximum destructive force of the material is equal to the average 8% (for tensile testing 14%, compression 2.5%, shear 6.5%), while the average coverage of the FEM characteristic with the results of the strength test in the field of elastic-plastic deformations with the adopted ±15% error overlap on average by about 77%. The analyses were performed in the ABAQUS/Standard 2020 program in the field of elastic-plastic deformations. Research with the use of numerical models after extension with a damage model will enable the design of energy-saving and durable grinding machines.


Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4145
Author(s):  
He Xue ◽  
Zheng Wang ◽  
Shuai Wang ◽  
Jinxuan He ◽  
Hongliang Yang

Dissimilar metal welded joints (DMWJs) possess significant localized mechanical heterogeneity. Using finite element software ABAQUS with the User-defined Material (UMAT) subroutine, this study proposed a constitutive equation that may be used to express the heterogeneous mechanical properties of the heat-affected and fusion zones at the interfaces in DMWJs. By eliminating sudden stress changes at the material interfaces, the proposed approach provides a more realistic and accurate characterization of the mechanical heterogeneity in the local regions of DMWJs than existing methods. As such, the proposed approach enables the structural integrity of DMWJs to be analyzed in greater detail.


2017 ◽  
Vol 730 ◽  
pp. 548-553
Author(s):  
Jing Ge ◽  
Hao Jiang ◽  
Zhen Yu Sun ◽  
Guo Jun Yu ◽  
Bo Su ◽  
...  

In this paper, we establish the mechanical property analysis of Single-walled Carbon Nanotubes (SWCNTs) modified beam element model based on the molecular structural mechanics method. Then we study the mechanical properties of their radial direction characteristics using the finite element software Abaqus. The model simulated the different bending stiffness with rectangular section beam elements C-C chemical force field. When the graphene curled into arbitrary chirality of SWCNTs spatial structure, the adjacent beam position will change the moment of inertia of the section of the beam. Compared with the original beam element model and the calculation results, we found that the established model largely reduced the overestimate of the original model of mechanical properties on the radial direction of the SWCNTs. At the same time, compared with other methods available in the literature results and the experimental data, the results can be in good agreement.


2012 ◽  
Vol 430-432 ◽  
pp. 525-529 ◽  
Author(s):  
Lin Chen ◽  
Ke Xin Bi

Using the finite element software ANSYS/LS-DYNA for the universal rolling machine to simulate,research unit of the universal rolling deformation etc, and the use of universal mill for heavy rail rolling to simulate of lead samples, study of both. By comparing experimental results, the results show rolling simulation of laboratory lead samples and finite element simulations of computer are basically the same, use the universal pass, the difference of pressure coefficient for the rail head and rail base and rail back that work on the workpiece at the universal pass is small, deformation of workpiece is uniformity, it ensure the dimensional accuracy of the finished rail on the rail section.


2011 ◽  
Vol 189-193 ◽  
pp. 3778-3781
Author(s):  
Yin Fang Jiang ◽  
Lei Fang ◽  
Zhi Fei Li ◽  
Zhen Zhou Tang

Laser shock processing is a technique similar to shot peening that imparts compressive residual stresses in materials for improved fatigue resistance. Finite element analysis techniques have been applied to predict the residual stresses from Laser shock processing. The purpose of this paper is to investigate of the different sheet thickness interactions on the stress distribution during the laser shock processing of 7050-T7451 aluminum alloy by using the finite element software. The results indicate that the sheet thickness has little effects on the compression stress in the depth of sheet, but great impacts on the reserve side.


Metals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1165 ◽  
Author(s):  
Hannes Fröck ◽  
Lukas Vincent Kappis ◽  
Michael Reich ◽  
Olaf Kessler

Age hardening aluminium alloys obtain their strength by forming precipitates. This precipitation-hardened state is often the initial condition for short-term heat treatments, like welding processes or local laser heat treatment to produce tailored heat-treated profiles (THTP). During these heat treatments, the strength-increasing precipitates are dissolved depending on the maximum temperature and the material is softened in these areas. Depending on the temperature path, the mechanical properties differ between heating and cooling at the same temperature. To model this behavior, a phenomenological material model was developed based on the dissolution characteristics and experimental flow curves were developed depending on the current temperature and the maximum temperature. The dissolution characteristics were analyzed by calorimetry. The mechanical properties at different temperatures and peak temperatures were recorded by thermomechanical analysis. The usual phase transformation equations in the Finite Element Method (FEM) code, which were developed for phase transformation in steels, were used to develop a phenomenological model for the mechanical properties as a function of the relevant heat treatment parameters. This material model was implemented for aluminium alloy 6060 T4 in the finite element software LS-DYNA (Livermore Software Technology Corporation).


Author(s):  
Ainhoa Martinez Ormaetxea ◽  
Andreas Öchsner

The manufacturing process of bone scaffold structures has an important influence on the final mechanical strength of the structure. When the structures are not produced properly, i.e. have imperfections such as missing parts or slightly displaced joints, they lose some of their mechanical properties. The aim of this study was to see how different types of damage affect the structures and also if their effects are equal when the structure is subjected to different load conditions. The change of the mechanical behavior was determined using the commercial finite element software MSC Marc Mentat. In turn, the damage was introduced by manipulating the structure’s files (ASCII data files) using the programming language Fortran. Apart from the numerical simulations, experimental testing was also performed to verify the numerical results. In the frame of this study, useful information for further research is provided.


2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Preeti Satheesh Kumar ◽  
Kumar K. S. Satheesh ◽  
Jins John ◽  
Geetha Patil ◽  
Ruchi Patel

Background and Objectives. A key factor for the long-term function of a dental implant is the manner in which stresses are transferred to the surrounding bone. The effect of adding a stiffener to the tissue side of the Hader bar helps to reduce the transmission of the stresses to the alveolar bone. But the ideal thickness of the stiffener to be attached to the bar is a subject of much debate. This study aims to analyze the force transfer and stress distribution of an implant-supported overdenture with a Hader bar attachment. The stiffener of the bar attachments was varied and the stress distribution to the bone around the implant was studied. Methods. A CT scan of edentulous mandible was used and three models with 1, 2, and 3 mm thick stiffeners were created and subjected to loads of emulating the masticatory forces. These different models were analyzed by the Finite Element Software (Ansys, Version 8.0) using von Mises stress analysis. Results. The results showed that the maximum stress concentration was seen in the neck of the implant for models A and B. In model C the maximum stress concentration was in the bar attachment making it the model with the best stress distribution, as far as implant failures are concerned. Conclusion. The implant with Hader bar attachment with a 3 mm stiffener is the best in terms of stress distribution, where the stress is concentrated at the bar and stiffener regions.


2011 ◽  
Vol 255-260 ◽  
pp. 952-956
Author(s):  
Jian Ping Sun ◽  
Jian Ping Chen ◽  
Gang Li

The reasons why the producing of the difference in temperature distributing and thermal stresses of box aqueduct under solar radiation are analyzed. The difference in temperature distributing and thermal stresses are effectively simulated by the finite element software ANSYS.The calculation results indicate that concrete box aqueduct body inter-surface whatever along the longitudinal and transverse will produce considerable thermal stresses under solar radiation, and its value has exceeded the design of concrete tensile strength. Therefore, the thermal stresses under the solar radiation must be considered in the design of box aqueduct body structural. We should appropriately configure temperature reinforcing steel bar.


Sign in / Sign up

Export Citation Format

Share Document