Investigation on the evaluation method and influencing factors of cross-scale mechanical properties of shale based on indentation experiment

The aim of this study is to develop a statistical estimation method of S-N curve for iron and structural steels by using their static mechanical properties. In this study, firstly, the S-N data for pure iron and structural steels were extracted from "Database on fatigue strength of Metallic Materials" published by the Society of Materials Science, Japan (JSMS) and S-N curve regression model was applied based on the JSMS standard, "Standard Evaluation Method of Fatigue Reliability for Metallic Materials -Standard Regression Method of S-N Curve-". Secondly, correlations between regression parameters and static mechanical properties were investigated. As a result, the relationship between the regression parameters and static mechanical properties (e.g. fatigue limit E and static tensile strength σB) showed strong correlations, respectively. Using these correlations, it is revealed that S-N curve for iron and structural steels can be predicted easily from the static mechanical properties.

Download Full-text

EVALUATION METHOD OF FLEXURAL CAPACITY FOR ASR DETERIORATED PRESTRESSED CONCRETE BEAM STRUCTURE WITH CRACK DENSITY AND MECHANICAL PROPERTIES OF DRILLED CORES

Journal of Japan Society of Civil Engineers Ser E2 (Materials and Concrete Structures) ◽

10.2208/jscejmcs.73.191 ◽

2017 ◽

Vol 73 (2) ◽

pp. 191-206

Author(s):

Yukio HIROI ◽

Takashi YAMAMOTO ◽

Yoshihiko TODA ◽

Yusuke TAKAGI

Keyword(s):

Mechanical Properties ◽

Prestressed Concrete ◽

Concrete Beam ◽

Evaluation Method ◽

Crack Density ◽

Flexural Capacity ◽

Beam Structure ◽

Prestressed Concrete Beam

Download Full-text

Monte Carlo Simulation for Exploring Mechanical Properties of Porous Materials Based on Scaled Boundary Finite Element Method

Applied Sciences ◽

10.3390/app12020575 ◽

2022 ◽

Vol 12 (2) ◽

pp. 575

Author(s):

Guangying Liu ◽

Ran Guo ◽

Kuiyu Zhao ◽

Runjie Wang

Keyword(s):

Mechanical Properties ◽

Finite Element Method ◽

Monte Carlo Simulation ◽

Finite Element ◽

Monte Carlo ◽

Porous Materials ◽

Influencing Factors ◽

Random Models ◽

Scaled Boundary Finite Element ◽

Element Method

The existence of pores is a very common feature of nature and of human life, but the existence of pores will alter the mechanical properties of the material. Therefore, it is very important to study the impact of different influencing factors on the mechanical properties of porous materials and to use the law of change in mechanical properties of porous materials for our daily lives. The SBFEM (scaled boundary finite element method) method is used in this paper to calculate a large number of random models of porous materials derived from Matlab code. Multiple influencing factors can be present in these random models. Based on the Monte Carlo simulation, after a large number of model calculations were carried out, the results of the calculations were analyzed statistically in order to determine the variation law of the mechanical properties of porous materials. Moreover, this paper gives fitting formulas for the mechanical properties of different materials. This is very useful for researchers estimating the mechanical properties of porous materials in advance.

Download Full-text

Evaluation Method of Granite Multiscale Mechanical Properties Based on Nanoindentation Technology

Geofluids ◽

10.1155/2021/6745900 ◽

2021 ◽

Vol 2021 ◽

pp. 1-9

Author(s):

Man Lei ◽

Fa-ning Dang ◽

Haibin Xue ◽

Mingming He

Keyword(s):

Mechanical Properties ◽

Elastic Modulus ◽

Uniaxial Compression ◽

Compression Test ◽

Evaluation Method ◽

Poisson Ratio ◽

Nanoindentation Test ◽

Uniaxial Compression Test ◽

Displacement Curve ◽

Mineral Contents

In order to study the mechanical properties of granite at the micro- and nanoscale, the load-displacement curve, residual indentation information, and component information of the quartz, feldspar, and mica in granite were obtained using a nanoindentation test, a scanning electron microscope (SEM), and X-ray diffraction (XRD). The elastic modulus and the hardness of each component of the granite were obtained through statistical analysis. Treating rock as a composite material, the relation between the macro- and microscopic mechanical properties of rock was established through the theory of micromechanical homogenization. The transition from micromechanical parameters to macromechanical parameters was realized. The equivalent elastic modulus and Poisson’s ratio of the granite were obtained by the Self-consistent method, the Dilute method, and the Mori-Tanaka method. Compared with the elastic modulus and the Poisson ratio of granites measured by a uniaxial compression test and the available data, the applicability of the three methods were analyzed. The results show that the elastic modulus and hardness of the quartz in the granite is the largest, the feldspar is the second, the mica is the smallest. The main mineral contents in granite were analyzed using the semiquantitative method by XRD and the rock slice identification test. The elastic modulus and the Poisson ratio of granite calculated by three linear homogenization methods are consistent with those of the uniaxial compression test. After comparing the calculation results of the three methods, it is found that the Mori-Tanaka method is more suitable for studying the mechanical properties of rock materials. This method has an important theoretical significance and practical value for studying the quantitative relationship between macro- and micromechanical indexes of brittle materials. The research results provide a new method and an important reference for studying the macro-, micro-, and nanomechanical properties of rock.

Download Full-text

Gum Tragacanth Fibers from Astragalus gummifer Species: Effects of Influencing Factors on Mechanical Properties of Fibers

Journal of Applied Sciences ◽

10.3923/jas.2007.2861.2865 ◽

2007 ◽

Vol 7 (19) ◽

pp. 2861-2865 ◽

Cited By ~ 9

Author(s):

Ramin Khajavi ◽

Seyed Hossein Mossav Pourgharbi ◽

Amir Kiumarsi ◽

Abosayeed Rashidi

Keyword(s):

Mechanical Properties ◽

Influencing Factors ◽

Gum Tragacanth ◽

Species Effects

Download Full-text

Study on mechanical properties and influencing factors of confined concrete arch in underground engineering with complex conditions

Arabian Journal of Geosciences ◽

10.1007/s12517-019-4786-1 ◽

2019 ◽

Vol 12 (21) ◽

Cited By ~ 2

Author(s):

Bei Jiang ◽

Qian Qin ◽

Qi Wang ◽

Shucai Li ◽

Hengchang Yu

Keyword(s):

Mechanical Properties ◽

Influencing Factors ◽

Confined Concrete ◽

Underground Engineering

Download Full-text

A Fuzzy Approach to Assess the Contractor’s Competitiveness

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.71-78.3946 ◽

2011 ◽

Vol 71-78 ◽

pp. 3946-3949 ◽

Cited By ~ 1

Author(s):

Na Dong ◽

Jing Zhang ◽

Min Jiu Yu

Keyword(s):

Influencing Factors ◽

Quantitative Evaluation ◽

Evaluation Method ◽

Comprehensive Evaluation ◽

Evaluation Criteria ◽

Qualitative Evaluation ◽

Fuzzy Comprehensive Evaluation ◽

Fuzzy Approach ◽

Fuzzy Comprehensive Evaluation Method ◽

Comprehensive Evaluation Method

A competitive contractor is the guarantee of project’s success, so how to choose a suitable contractor is critical for the owners. However, among the influencing factors considered in the selection, some can be quantitatively evaluated with clear evaluation criteria while others can only be qualitative evaluated so that no specific scores can be obtained. For the above reasons an improved fuzzy comprehensive evaluation method is proposed in which all assessment factors are divided into two categories and are evaluated with different criteria. The method integrates the advantage of quantitative evaluation and qualitative evaluation. Finally it is verified by a case and the result shows that the application of the improved fuzzy approach to choose contractor is effective and reasonable.

Download Full-text

Experimental study on laminated bamboo lumber column

E3S Web of Conferences ◽

10.1051/e3sconf/20183802001 ◽

2018 ◽

Vol 38 ◽

pp. 02001 ◽

Cited By ~ 1

Author(s):

Chenwei Wang ◽

Huizhong Zhang ◽

Chenjie Zhao ◽

Chenge Zhang ◽

Tongwei Cao ◽

...

Keyword(s):

Mechanical Properties ◽

Experimental Study ◽

Tensile Stress ◽

Bearing Capacity ◽

Influencing Factors ◽

Ultimate Load ◽

Eccentric Compression ◽

Laminated Bamboo ◽

Standard Normal ◽

Laminated Bamboo Lumber

This paper presents and discusses the experimental study on the mechanical properties of LBL column both under axial and eccentric compression. The results shows that the ultimate load for the eccentric compression specimens with the eccentricity values of 30 mm and 110 mm are 95.2 kN and 31.8 kN respectively. Eccentricity is one of the main influencing factors for the ultimate bearing capacity of the LBL columns. Because of the vulnerability of the mechanical connections or natural nodes to tensile stress and secondly, laminated bamboo is vulnerable to defects that has more detrimental influence on the tensile resistance of the material. The variation in strain for the laminated bamboo lumber column sections is linear throughout the loading process, following standard normal section bending theory which is similar as that for the beam.

Download Full-text