scholarly journals Numerical and Experimental Study on Modular-Based Timber Structures

Author(s):  
Sigurdur Ormarsson ◽  
Johan Vessby ◽  
Marie Johansson ◽  
Le Kua

Building with prefabricated light-frame volume modules is a prevalent and innovative construction method for low and mid-rise timber buildings. Compared to traditionally site-built constructions this method is very advantageous due to its high prefabrication level and the fast on-site assembly of the modules. The focus of this project is to study and optimise the global shear stiffness of the volume modules and to secure a large enough shear and uplift stiffness of the mechanical (or friction based) connections between the modules. Some companies assume that the friction between the modules is sufficient to transfer the wind stabilization forces down through the entire building. Regarding structural safety, connection design is an important task that needs to be numerically studied and experimentally verified. The paper presents numerical and experimental results obtained from two ongoing research projects concerning modular-based timber buildings in Sweden. The final aim of this work is to develop an efficient three dimensional finite-element model to analyse both the global and detailed structural behaviour of these types of buildings. To study the overall shear stiffness of the volume modules, eight different test-modules are to be tested. The test results will be used to calibrate the numerical model.

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Kaizhong Xie ◽  
Hongwei Wang ◽  
Jianxi Zhou ◽  
Xiao Luo ◽  
Miao Yue

In order to study a new reinforcement method for multilayer (4 layers) industrial building’s vibration, firstly, a new reinforcement method using a short-pier shear wall was put forward. Secondly, an engineering example of a multilayer industrial building with abnormal vibration was introduced. A three-dimensional finite element model of multilayer industrial building was established, and field vibration test was carried out. Test results showed that abnormal vibration of industrial building was caused by resonance between machines and multilayer industrial building. Finally, multilayer industrial building was reinforced by a new reinforcement method, and vibration experiment was carried out after reinforcement. The results show that the new reinforcement method has a good reinforcement effect. Strength and stiffness of multilayer industrial building were obviously improved, and natural frequency of industrial building in the length direction increased from 2.45 Hz to 5.87 Hz, natural frequency of industrial building in the width direction increased from 2.94 Hz to 7.83 Hz, frequencies of machines and frequencies of multilayer industrial building were not in resonance range, acceleration and velocity vibration characteristics of multilayer industrial building were improved, which can provide reference for the reinforcement of multilayer industrial building with a similar structural configuration.


2008 ◽  
Vol 22 (09n11) ◽  
pp. 1403-1408 ◽  
Author(s):  
DONG-HYUN KIM ◽  
YU-SUNG KIM

In this study, nonlinear crash analyses have been conducted for the skid landing gear of helicopter. The realistic configuration of skid landing gear system is considered. Detailed three-dimensional finite element model with variable thickness and material nonlinearity is constructed for required impact design conditions. Advanced computational approach is used to conduct nonlinear transient impact dynamic analyses for different collision models. Characteristics of impact dynamic responses due to the ground crash are practically investigated in detail. It is also shown that the exact consideration of friction effect is very important to accurately predict the crash behavior of the skid type landing gear system. Finally, two typical landing conditions are analyzed and correlated with drop test results.


Author(s):  
I. P. Pasqualino ◽  
M. I. Lourenc¸o ◽  
T. A. Netto

Sandwich pipes have been considered feasible conceptions for ultra deepwater pipelines, since they are capable to work at low temperatures and withstand high hydrostatic pressures. Sandwich pipelines are composed by inner and outer metallic pipes and a suitable core material which must provide high compression strength and good thermal insulation. The aim of this ongoing research is to study the quasi-static propagation of buckles in sandwich pipes. In this paper, a three-dimensional finite element model considering material and geometric nonlinear behavior is presented. The mesh discretization is determined through a detailed mesh sensitivity analysis. Some experiments with small scale models combining aluminum pipes and polypropylene as core material were carried out to calibrate the numerical model. The propagation pressure is evaluated under different bonding conditions between pipe layers.


2019 ◽  
Vol 12 (3) ◽  
Author(s):  
Abdulnasser Mohammed Abbas

Nowadays, the deep beams become utilized more in a considerable number of structures. It is necessary sometimes to introduce a hole within the web of the beam as a pipe or a duct for many purposes such as water supply, sewage, electricity, air conditioning, and computer network. In this study, a deep beam sample taken from a past experimental study is numerically analysed using a three-dimensional finite element model. ABAQUS tools are used to simulate the whole FE models.  The dimensions of the considered deep beam are 820x400x180 mm, with two openings of a diameter 90 mm located at 200 mm from both of the ends. The proposed model and the experimental work have reasonably agreed with a difference of 2 % in mid-span deflection. Furthermore, special reinforcements of 12 mm bar diameter are offered to the original FE model around the holes in two types, Z-shape and circular, to improve the structural behaviour of the deep beam and to minimize the crack concentrations in these zones. The gained results show that the additional reinforcement minimizes the mid-span deflection of the deep beam. As compared with the original proposed FE model, the Z-shape decreases the deflection by 44.9 % while the lowering in the defection of the circular shape is 9.4 %. Moreover, the concentration of stresses and cracks that gained from using the Z-shape reinforcement model found to be lower than those induced in the circular reinforcement model.


2010 ◽  
Vol 163-167 ◽  
pp. 3694-3700 ◽  
Author(s):  
Qiang Jia ◽  
Xiao Meng ◽  
Xin Zhang

Differential settlement of the new foundation was produced after the building monolithic moving was finished. The internal forces of the top building were changed due to the existence of the differential settlement and the original differential settlement, which affected structural safety. A three-dimensional finite element model was established based on the ANSYS program to attain the foundation settlement law of a fifteen-story moving building. Through calculation and comparation of the settlement values and differential settlement between slab foundation and pile foundation, the pile foundation was finally selected as the construction scheme. Simultaneously, numerical analysis of foundation differential settlement during the moving process was performed. The monitoring results were showen to be in reasonable agreement with the numerical analysis results.


2007 ◽  
Vol 35 (3) ◽  
pp. 226-238 ◽  
Author(s):  
K. M. Jeong ◽  
K. W. Kim ◽  
H. G. Beom ◽  
J. U. Park

Abstract The effects of variations in stiffness and geometry on the nonuniformity of tires are investigated by using the finite element analysis. In order to evaluate tire uniformity, a three-dimensional finite element model of the tire with imperfections is developed. This paper considers how imperfections, such as variations in stiffness or geometry and run-out, contribute to detrimental effects on tire nonuniformity. It is found that the radial force variation of a tire with imperfections depends strongly on the geometrical variations of the tire.


2021 ◽  
Vol 11 (5) ◽  
pp. 2225
Author(s):  
Fu Wang ◽  
Guijun Shi ◽  
Wenbo Zhai ◽  
Bin Li ◽  
Chao Zhang ◽  
...  

The steel assembled support structure of a foundation pit can be assembled easily with high strength and recycling value. Steel’s performance is significantly affected by the surrounding temperature due to its temperature sensitivity. Here, a full-scale experiment was conducted to study the influence of temperature on the internal force and deformation of supporting structures, and a three-dimensional finite element model was established for comparative analysis. The test results showed that under the temperature effect, the deformation of the central retaining pile was composed of rigid rotation and flexural deformation, while the adjacent pile of central retaining pile only experienced flexural deformation. The stress on the retaining pile crown changed little, while more stress accumulated at the bottom. Compared with the crown beam and waist beam 2, the stress on waist beam 1 was significantly affected by the temperature and increased by about 0.70 MPa/°C. Meanwhile, the stress of the rigid panel was greatly affected by the temperature, increasing 78% and 82% when the temperature increased by 15 °C on rigid panel 1 and rigid panel 2, respectively. The comparative simulation results indicated that the bending moment and shear strength of pile 1 were markedly affected by the temperature, but pile 2 and pile 3 were basically stable. Lastly, as the temperature varied, waist beam 2 had the largest change in the deflection, followed by waist beam 1; the crown beam experienced the smallest change in the deflection.


2007 ◽  
Vol 129 (6) ◽  
pp. 1028-1034 ◽  
Author(s):  
Liang Wang ◽  
Sergio Felicelli

A three-dimensional finite element model was developed to predict the temperature distribution and phase transformation in deposited stainless steel 410 (SS410) during the Laser Engineered Net Shaping (LENS™) rapid fabrication process. The development of the model was carried out using the SYSWELD software package. The model calculates the evolution of temperature in the part during the fabrication of a SS410 plate. The metallurgical transformations are taken into account using the temperature-dependent material properties and the continuous cooling transformation diagram. The ferritic and martensitic transformation as well as austenitization and tempering of martensite are considered. The influence of processing parameters such as laser power and traverse speed on the phase transformation and the consequent hardness are analyzed. The potential presence of porosity due to lack of fusion is also discussed. The results show that the temperature distribution, the microstructure, and hardness in the final part depend significantly on the processing parameters.


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