scholarly journals The Linear Hygroscopic Expansion Coefficient of Cement-Based Materials and Its Determination

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 37
Author(s):  
Depeng Chen ◽  
Qilin Zhu ◽  
Zhifang Zong ◽  
Tengfei Xiang ◽  
Chunlin Liu

A crack caused by shrinkage could remarkably increase the permeability, heavily deteriorate the durability, and heavily deteriorate the service life of a concrete structure. However, different forms of thermal shrinkage can be predicted by directly applying a temperature load on a node. The prediction of moisture-induced stresses in cement-based materials by using the common finite element method (FEM) software is a big challenge. In this paper, we present a simple numerical calculation approach by using the proposed coefficient of hygroscopic expansion (CHE) to predict the moisture-induced deformation of concrete. The theoretical calculation formula of the linear CHE (LCHE) of cement-based material was deduced based on the Kelvin–Laplace equation and the Mackenzie equation. The hygroscopic deformation of cement mortar was investigated by inversion analysis; based on the results, the LCHE could be determined. Moreover, a case analysis of the application of LCHE to concrete is also conducted. The simulated results of concrete shrinkage were close to the experimental ones. As a whole, it is feasible to predict the drying shrinkage of concrete through simple calculation by using the proposed LCHE, which is also beneficial to the direct application of moisture loads on nodes in finite element analysis (FEA).

2014 ◽  
Vol 1065-1069 ◽  
pp. 1226-1229
Author(s):  
Yong Sheng Zhang ◽  
Yan Ying Li

Basing on the finite element analysis software, the emergence of crack under the effect of gradual changed temperature load and the change of stress which are in the condition of super reinforced concrete frame structure are analyzed from the linear and nonlinear numeral simulation. The simulation shows that the structure component under the normal condition is cracked and turn into the nonlinear condition and the steel bars still works under the elastic stage. Meanwhile the actual stage which is reflected by the elastic-plastic analysis of the internal force and deformation is compared by the results which are obtained by the actual project observed results and the calculation of the simplified model. So the distribution of the stress which is caused by the structure temperature reduction is greatly evaluated by the usage of the cracking model which is nonlinear finite element and also plays an important role in the engineering project and practice.


Author(s):  
Koen Dwarshuis ◽  
Ronald Aarts ◽  
Marcel Ellenbroek ◽  
Dannis Brouwer

Abstract Flexure joints are rapidly gaining ground in precision engineering because of their predictable behavior. However the range of motion of flexure joints is limited due to loss of support stiffness in deformed configurations. Most of the common flexure joints consist of prismatic leaf springs. This paper presents a simple non-prismatic beam formulation that can be used for the efficient modelling of non-prismatic leaf springs. The resulting stiffness and stress computed by the non-prismatic beam element are compared to the results of a finite element analysis. The paper shows that the support stiffness of two typical flexure joints can be increased up to a factor of 1.9 by using non-prismatic instead of prismatic leaf springs.


2012 ◽  
Vol 468-471 ◽  
pp. 2413-2416 ◽  
Author(s):  
Chuang Du ◽  
Yan Yan Li ◽  
Rong Guo ◽  
Shi Bin Ma

In order to study the performance of asphalt pavement with function layer under temperature-load coupling action, the thickness of surface layer, the module of surface layer and was analyzed to abtain their influence on the function layer stress using the finite element method. The results clearly indicated that it is very effective to prevent the reflection crack by increasing the thickness of asphalt surface layer and it is not obvious to reduce the reflection crack through enhancing the module of asphalt surface layer.


Author(s):  
Sayed A. Nassar ◽  
Amir Kazemi ◽  
Mohamad Dyab

Experimental and Finite Element methods are used for investigating the effect of cyclic thermal loading on the clamp load decay in preloaded single-lap bolted joints that are made of dissimilar-materials. Joint material combinations include steel and lightweight materials such as aluminum and magnesium alloys, with various different thicknesses. The range of cyclic temperature profile varies between −20°C and +150°C. A computer-controlled environmental chamber is used for generating the desired cyclic temperature profile and duration. Real time clamp load data is collected using high-temperature load cells. Percent clamp load decay is investigated for various combinations of joint materials, initial preload level, and test specimen thicknesses. Thermal and material creep finite element analysis is performed using temperature-dependent mechanical properties. FEA result has provided insight into interesting experimental observations regarding model predictions and the experimental data is discussed.


2004 ◽  
Vol 32 (1) ◽  
pp. 2-22 ◽  
Author(s):  
B. Chen

Abstract Thermal-mechanical properties of tire cords have a great influence on tire dimension, shape, handling, and other performance related issues. This study focuses on characterizing the material properties for polymeric cords and quantifying their effects on pneumatic tires using finite element analysis (FEA). Various tire cord materials, including nylon and polyester, were characterized by obtaining a series of thermal-mechanical properties in the laboratory using tensile testing, thermal shrinkage measurement and creep testing. Prior to obtaining these laboratory measurements, cords in this study were subjected to thermal-mechanical pre-treatments to simulate the effects of curing and tire operating conditions. The properties derived from these measurements were used as input properties for a finite element analysis of a physical tire. Predictions of tire dimensions and shape, loaded footprint and pressure and cord loads were obtained from the FEA model and compared to measured values of the experimental tire. Good agreement was observed between the measured values and those predicted from the finite element analysis; therefore, future FEA studies of pneumatic tires should utilize the techniques developed in this study to characterize tire cord materials.


2015 ◽  
Vol 773-774 ◽  
pp. 33-37 ◽  
Author(s):  
Izzuddin Zaman ◽  
Muhammad Mohamed Salleh ◽  
Bukhari Manshoor ◽  
Amir Khalid ◽  
Mohd Zamani Ngali ◽  
...  

There are many ways to control the vibration of plate structure. Conventional approaches that include structural alterations are frequently time consuming and costly. One of the common schemes is using vibration absorber attached to a structure. In this paper, a mathematical model is developed to determine the frequency response of fixed-fixed ends plate with attached vibration absorber. A finite element analysis was performed and compared with the theoretical predictions and showed that there was good resemblance. The results demonstrated that the addition of vibration absorber onto plate can attenuate vibration considerably at a constant frequency.


2012 ◽  
Vol 446-449 ◽  
pp. 353-357
Author(s):  
Yan Xin Zhang ◽  
Li Ping Tong

This paper takes the rammed earth buildings as the research object and summarizes their common defects. Finite element analysis method is used to analyze the cause of the common defects. These will provide a reference for improving the seismic behavior of these buildings.


2012 ◽  
Vol 594-597 ◽  
pp. 1498-1503
Author(s):  
Heng Shan Gao ◽  
Tie Ying Li

In this paper, using the universal finite element analysis software SAP2000 to build a large span cable-stayed bridge with finite element model, using a stepwise analysis finite element method to study the concrete shrinkage and creep efforts on the main beam inner force and deformation, cable tension during the cable-stayed bridge construction process and after the bridge. Research results show that the effects of shrinkage and creep in the finished bridge cannot be ignored, and the results can be used as reference for the design of similar projects.


2014 ◽  
Vol 1004-1005 ◽  
pp. 1455-1459
Author(s):  
Wei Hong Xuan ◽  
Pan Xiu Wang ◽  
Yu Zhi Chen ◽  
Yan Wang ◽  
Xiao Hong Chen ◽  
...  

In this paper, the temperature stress of singer piece was calculated by FEM and the stress reaction of PP fiber and steel fiber was analyzed. It is knew that the fiber with lower elastic modulus and lagerer spacing can provide weaker constraints and the restriction stress of fiber concrete is smaller. The calculation result of fiber reason space between is consistent with the common value in engineering.


Sign in / Sign up

Export Citation Format

Share Document