scholarly journals Effect of Bamboo Nodes on the Mechanical Properties of P. edulis (Phyllostachys Edulis) Bamboo

Forests ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1309
Author(s):  
Pengcheng Liu ◽  
Qishi Zhou ◽  
Feiyang Fu ◽  
Wei Li

In the context of global sustainable development, the use of natural and renewable bamboo as a building material is of great significance for building engineering. As an important part of bamboo, there is still a lack of systematic research on the effect of bamboo nodes on the mechanical properties of bamboo. In this paper, compression parallel to the grain of the bamboo, bending, tensile parallel to the grain, shear parallel to the grain, compression perpendicular to the grain and tensile perpendicular to the grain tests of an entire bamboo culm of P. edulis bamboo were carried out, and the effects of bamboo nodes on moisture content, bearing capacity and mechanical properties were analyzed. The relationship between the mechanical properties and standardized parameters of the node and internode specimens was established. A conversion method of mechanical properties of the same test type was proposed, and a conversion method among different mechanical properties was proposed. The bamboo was graded by tensile strength parallel to the grain. The results show that bamboo nodes have an obvious effect on the moisture content. Bamboo nodes have different effects on the bearing capacity and mechanical properties of different types of specimens. The mechanical properties of P. edulis bamboo can be predicted by the relationship between the mechanical properties and the standardized parameters and the mechanical property conversion method. The strength classification of P. edulis bamboo can be predicted by standardized parameters.

2020 ◽  
Vol 980 ◽  
pp. 266-274
Author(s):  
Jian Hua Xiao ◽  
Miao Liu ◽  
Jin Li Wang ◽  
Abdulhamid Yakubu Anvah

In order to investigate the shear capacity of prefabricated beam, experiments about shear bearing were performed on one integral pouring contrast beam and two prefabrication and assembly beams. Inspecting the relationship between load and deflection under the load, the development regularity of strain between longitude reinforced and stirrup, the shear capacity of cracking load and ultimate bearing capacity, analyzing failure mode of oblique section and connection performance of old and new concrete in the groove, and compared with the mechanical properties of cast-in-place concrete beam. The experimental results indicate that: prefabrication and assembly beam and cast-in-place beams have similar shear bearing capacity and failure mode of oblique section, along with the load level continues to increase, the groove joint stiffness weakened, but has little effect on the overall deformation.


2019 ◽  
Vol 944 ◽  
pp. 351-356
Author(s):  
Sheng Rui Su ◽  
Ren Bo Song ◽  
Chi Chen ◽  
Wen Sheng Ji ◽  
Shi De Li ◽  
...  

The microstructure and mechanics of 15CrNiMo steel with different quenching temperatures (800°C, 825°C, 850°C, 875°C, 900°C) and different quenching holding time (15min, 25min, 35min) were studied for steel 15CrNiMo for roller bit. The relationship between the properties of different quenching parameters and the mechanical properties such as microstructure, impact toughness and hardness was analyzed. The results show that the microstructure of the annealed precursor is mainly ferrite and pearlite. With the increase of quenching temperature, the ferrite is gradually reduced, the lath martensite is gradually increased, and the martensite grains tend to grow. The strength increases first and then decreases, and the plasticity increases slightly. The quenching and holding time has no obvious effect on the test steel, and the austenitization of the core is the best time. The best quenching temperature is 850°C, the best holding time is 25 min, (tempering temperature is 220°C, tempering holding time is 50 min) and the mechanical properties are optimal.


2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Kesheng Li ◽  
Maotong Li ◽  
Deng Zhang ◽  
Chuanxiao Liu ◽  
Depeng Ma

Moisture content (MC) and freeze-thaw (F-T) process have an important influence on the mechanical properties of rock and its rockburst tendency in the cold region. In addition, uniaxial compressive strength (UCS) of rock is of great importance in evaluating weathering durability, frost resistance, and bursting liability of rock. In this study, the UCS of rock and bursting liability index of rock including elastic energy index (WET), impact energy index (WCF), elastic strain energy index (ES), and modified values of brittleness index (BIM) were measured by laboratory tests. These tests were implemented in six different MC (0, 0.58, 1.06, 1.82, 2.43, and 2.80%) and 20 F-T cycles. The relationship between rock mechanical properties, bursting liability of rock, and MC after freeze-thaw damage was established, and the control mechanism of moisture content on mechanical properties and rockburst tendency of rocks in cold regions was revealed. Uniaxial compressive test results showed that the UCS of rock decreases significantly with the increase of MC. Under the action of F-T cycles, WET, WCF, and ES decrease with the increase of MC, and BIM of rock increases gradually. This indicates that the rockburst tendency of sandstone decreases with the increase of MC. To calculate WET, WCF, ES, and BIM of sandstone samples, new empirical equations were established and put forward under different MC after 20 F-T cycles.


Author(s):  
X. Liu ◽  
R. D. Wildman ◽  
I. A. Ashcroft ◽  
A. E. Elmahdy ◽  
P. D. Ruiz

A hygromechanical model has been developed to simulate the in-service behaviour of the natural lacquer urushi , using a phenomenological description of viscoelasticity. The material and mechanical properties were determined as a function of the relative humidity (RH), and the relationship between RH and moisture content was determined. These properties served as inputs to a finite-element-based model that was then tested against experimental measurements of the depth-averaged stresses in a thin layer of urushi deposited on a substrate and exposed to changes in the environmental conditions. Good agreement was seen between the predicted and measured behaviour. The validated model was used to investigate the spatial and temperature variation of stress in urushi films subjected to cyclic environmental conditioning.


2011 ◽  
Vol 255-260 ◽  
pp. 4193-4196
Author(s):  
Jian Suo Ma ◽  
Run Shan Bai ◽  
Yong Hao

Using BFRPS to increase strength and durability of the structure has recently started to be used as a new technical mean. In this paper, eight BFRPS timber columns under axial compressive loads are tested, and damage characteristics and mechanical properties are studied based on the testing results. Compared with the components which are reinforced and not, the relationship between the effects of bearing factors and increasing degrees can be concluded, providing reference for the similar engineering problems.


1999 ◽  
Vol 33 (3) ◽  
pp. 283-289 ◽  
Author(s):  
Tooru Sugawara ◽  
Mizue Kawai ◽  
Hitoshi Hosokawa ◽  
Toshiyuki Suzuki

Sign in / Sign up

Export Citation Format

Share Document