scholarly journals Study on Safety Performance of Building Finish Layer under Thermomechanical Coupling Condition

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Kai Yan ◽  
Yansong Hu ◽  
Kaozhong Zhao ◽  
Xin Lin

The building finish layer is a comprehensive structural system including the building exterior insulation system and building exterior finish. Combining with buildings has the advantage of reducing wall heat loss and building deformation caused by large temperature differences. Since the building finish layer is prone to cracking, hollowing, and peeling, during the application process, its safety needs to be studied and certified. This study prepares 20 groups of specimens, 15 anchor bolts in each group. The anchor bolt pull-out strength test is carried out. Anchoring damage evolution law and failure mode of anchor bolts are investigated. And the influence of anchoring methods on the pull-out bearing capacity is analyzed. In addition, ABAQUS finite element data simulation is carried out. The stress state of finish in thermomechanical coupling condition and without the effect of temperature are compared and analyzed. The influence factors of anchor bolt pull-out strength and the influence of temperature load on the long-term performance of building finish layer are obtained. The durability of the building finish layer is analyzed. The results show that the anchoring strength of the anchor bolt is positively correlated with the anchoring depth. The anchoring strength is influenced significantly by anchoring construction sequence and temperature. The stress under the coupled effect of temperature and load is greater than that of the single effect of load, and the stress distribution changes significantly. Due to thermal expansion and contraction, the anchor bolt would loosen, which is more prone to damage the building finish layer in a low temperature environment. The weight relationship of each influencing factor of the building finish layer is proposed. A systematic evaluation index system is established. The results of this study provide a basis for subsequent related research work and engineering applications.

2021 ◽  
Vol 11 (18) ◽  
pp. 8526
Author(s):  
Chi Lu ◽  
Yoshimi Sonoda

As an important method for connecting structural members, anchor bolts have been installed in many situations. Therefore, accurate evaluation of the pull-out strength of anchor bolts has always been an important issue, considering the complicated actual installation conditions and the problem of aging deterioration of the structural members. In general, the patterns of pull-out failure of anchor bolts can be classified into three types: adhesion failure, cone failure, and bolt break. However, it sometimes shows a mixed fracture pattern, and it is not always easy to predict the accurate pull-out strength. In this study, we attempted to evaluate the pull-out strength of anchor bolts under various installation conditions using SPH, which can analyze the crack growth process in the concrete. In particular, the anchor bolt-concrete interface model was introduced to SPH analysis in order to consider the bond failure, and it was confirmed that various failure patterns and the load capacity could be predicted by proposed SPH method. After that, the influence of several parameters, such as bond stress limit, anchor bolt diameter, and the anchor bolt embedment depth on the failure patterns and the load capacity, were investigated by numerical calculation. Furthermore, several useful suggestions on the pull-out strength of anchor bolts under improper installation conditions, such as the ends of members for the purpose of seismic retrofitting, are presented.


2016 ◽  
Vol 711 ◽  
pp. 1111-1117 ◽  
Author(s):  
Yoshimi Sonoda

The strength of an anchor bolt in concrete structure under pull-out load is usually designed by three possible failure modes such as fracture of anchor bolt, cone failure of concrete and bond failure between anchor bolt and concrete. In general, the design load is considered the smallest load corresponding to the aforementioned failure mechanisms. However, unexpected failure often occurs in the anchorage zone due to the complex failure or the change of failure condition. Therefore, it is important to develop the accurate analysis method of ultimate load bearing capacity of the anchor bolt. In this study, we conducted an analytical study using Adaptive Smoothed Particle Hydrodynamics (ASPH) in order to simulate the failure process of anchorage zone and discussed the effect of embedment depth of anchor bolts on their ultimate strength.


2012 ◽  
Vol 212-213 ◽  
pp. 904-911
Author(s):  
Xie Xing Tang ◽  
Xiao Yong Luo ◽  
Kai Lei Li ◽  
Ya Chuan Kuang

In practical projects, GFRP anchor bolts are in complex geological conditions with corrosive factors such as acid, alkalis, salt and freeze-thaw circle. In corrosive conditions, the bonding strength of GFRP anchor bolts are in direct relation to safety of anchoring works. Based on comparative tests on bonding strength between GFRP anchor bolt and concrete, failure modes in pull-out tests of GFRP anchor bolt and concrete are mainly pull-out failure and splitting failure. Pull-out failure is a chemical and mechanical interlocking failure between GFRP anchor bolts and concrete cubes, which can actually reflect the bonding status of bolts and concrete cubes. Splitting failure is a failure that the radial expansion force caused when the GFRP anchor bolt are bearing forces damages the concrete if it is of low strength or insufficient in thickness of protection layer and thus leads to boding failure. From the analysis on test results of bond-slip performance, the bonding strength decline the most in alkalis conditions: the bonding strength decreases by 23% after 1500 hours of corrosion and the slip displacement increases by 2.4mm; in acid and salt conditions, after 1500 hours of corrosion the bonding strength decreases by 19% and 17% and slip displacement increase by 1.6mm and 1.8mm, respectively. Based on analysis of nonlinear curve fitting on test data of bonding strength in three corrosive conditions, three empirical equations of degradation of bonding strength are fitted for GFRP anchor bolts in three corrosive conditions. Compared with data from reference [13], the bonding strength of GFRP anchor bolts working in acid, alkalis and salt geological conditions for 50 years decrease by 19.5%, 25% and 19.2%, respectively. These research results supply a test basis for GFRP anchor bolts used in complex geological conditions.


2009 ◽  
Vol 34 (5) ◽  
pp. 643-650 ◽  
Author(s):  
H. OMAE ◽  
C. ZHAO ◽  
Y.-L. SUN ◽  
M. E. ZOBITZ ◽  
S. L. MORAN ◽  
...  

The purpose of this study was to assess tendon metabolism and suture pull-out strength after simple tendon suture in a tissue culture model. One hundred and twelve flexor digitorum profundus tendons from 28 dogs were cultured for 7, 14, or 21 days with or without a static tensile load. In both groups increased levels of matrix metalloproteinase (MMP) mRNA was noted. Suture pull-out strength did not decrease during tissue culture. While the presence of a static load had no effect on the pull-out strength, it did affect MMP mRNA expression. This tissue culture model could be useful in studying the effect of factors on the tendon-suture interface.


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