scholarly journals 2D- and 3D-explosive experiments for verification of spall and shear strength models for some steels

2012 ◽  
Author(s):  
Evgeny Alexander Kozlov
Keyword(s):  
Shear Strength ◽  
Strength Models ◽  
2D And 3D

scholarly journals Shear Strength of Internal Reinforced Concrete Beam-Column Joints: Intelligent Modeling Approach and Sensitivity Analysis

2020 ◽  
Vol 2020 ◽  
pp. 1-19
Author(s):  
De-Cheng Feng ◽  
Bo Fu
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Influence Factors ◽  
Regression Tree ◽  
Reinforced Concrete Beam ◽  
Gradient Boosting ◽  
Intelligent Modeling ◽  
Modeling Approach ◽  
Ensemble Machine Learning ◽  
Strength Models

In this paper, an intelligent modeling approach is presented to predict the shear strength of the internal reinforced concrete (RC) beam-column joints and used to analyze the sensitivity of the influence factors on the shear strength. The proposed approach is established based on the famous boosting-family ensemble machine learning (ML) algorithms, i.e., gradient boosting regression tree (GBRT), which generates a strong predictive model by integrating several weak predictors, which are obtained by the well-known individual ML algorithms, e.g., DT, ANN, and SVM. The strong model is boosted as each weak predictor has its own weight in the final combination according to the performance. Compared with the conventional mechanical-driven shear strength models, e.g., the well-known modified compression field theory (MCFT), the proposed model can avoid the complicated derivation process of shear mechanism and calibration of the involved empirical parameters; thus, it provides a more convenient, fast, and robust alternative way for predicting the shear strength of the internal RC joints. To train and test the GBRT model, a total of 86 internal RC joint specimens are collected from the literatures, and four traditional ML models and the MCFT model are also employed as comparisons. The results indicate that the GBRT model is superior to both the traditional ML models and MCFT model, as its degree-of-fitting is the highest and the predicting dispersion is the lowest. Finally, the model is used to investigate the influences of different parameters on the shear strength of the internal RC joint, and the sensitivity and importance of the corresponding parameters are obtained.

Shear strength of interfaces in natural and in recycled aggregate concrete

2017 ◽  
Vol 44 (3) ◽  
pp. 212-222
Author(s):  
Shakeel Ahmad Waseem ◽  
Bhupinder Singh
Keyword(s):  
Shear Strength ◽  
Shear Plane ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Failure Envelope ◽  
Interface Shear ◽  
Aggregate Concrete ◽  
Normal Strength ◽  
Strength Models

Shear strength of interfaces in natural aggregate concrete and in recycled aggregate concrete has been investigated using initially uncracked push-off specimens by varying the following parameters: replacement level of the recycled aggregates (0%, 50%, and 100%), concrete grade (normal-strength and medium-strength), and clamping force on the shear plane. Development of truss action for resisting interface shear was indicated by the observed crack patterns in the tested specimens and a truss-based analysis recommended in the literature in combination with a simplified failure envelope for concrete subjected to biaxial stresses has been used for shear strength predictions of the tested specimens. The proposed methodology, which is considered to be more rational than the empirical shear strength models available in the literature was calibrated for both the concrete types and gave conservative and reasonably accurate shear strength predictions for selected experiments taken from the literature.

scholarly journals The ARMR Classification System and the Modified Hoek-Brown Failure Criterion Compared to Directional Shear Strength Models for Anisotropic Rock Masses

2019 ◽  
Author(s):  
Neil Bar ◽  
Charalampos Saroglou
Keyword(s):  
Shear Strength ◽  
Rock Mass ◽  
Failure Criterion ◽  
Classification System ◽  
Failure Criteria ◽  
Rock Masses ◽  
Anisotropic Rock ◽  
Anisotropic Rock Mass ◽  
Degree Of Anisotropy ◽  
Strength Models

The anisotropic rock mass rating classification system, ARMR, has been developed in conjunction with the Modified Hoek-Brown failure to deal with varying shear strength with respect to the orientation and degree of anisotropy within an anisotropic rock mass. Conventionally, ubiquitous-joint or directional shear strength models have assumed a general rock mass strength, typically estimated using the Hoek-Brown failure criterion, and applied a directional weakness in a given orientation depending on the anisotropic nature of the rock mass. Shear strength of the directional weakness is typically estimated using the Barton-Bandis failure criterion, or on occasion, the Mohr-Coulomb failure criteria. Directional shear strength models such as these often formed the basis of continuum models for slopes and underground excavations in anisotropic rock masses. This paper compares ARMR and the Modified Hoek-Brown failure criterion to the conventional directional shear strength models using a case study from Western Australia.

scholarly journals The Shear Strength of Granite Weathered Soil Under Different Hydraulic Paths

2020 ◽  
Vol 10 (18) ◽  
pp. 6615
Author(s):  
Youqian Lu ◽  
Guoqing Cai ◽  
Chenggang Zhao
Keyword(s):  
Shear Strength ◽  
Direct Contact ◽  
Clear Understanding ◽  
Soil Mineral ◽  
Strength Index ◽  
Soil Particles ◽  
Weathered Soils ◽  
Weathered Soil ◽  
The Difference ◽  
Strength Models

At present, there is no clear understanding of the influence of differences in soil mineral composition, particle size grading, and hydraulic paths on the shear strength of unsaturated soil, and the related strength models are not applicable. The shear strength characteristics of different saturation specimens under different hydraulic paths were studied on two granite weathered soils. The experimental results show that the shear strength index of the prepared specimen is “arched” with the increase of saturation, and the dehydration specimen decreases linearly with the saturation. As considering the cementation of free oxides in soils and the interaction among soil particles at different saturations, it is assumed that there are three different contact modes among soil particles: direct contact, meniscus contact, and cement contact. The difference in contact modes will reflect the different laws of shear strength. A shear strength model capable of distinguishing between the capillary effect and the adsorptive effect was established. The model predicted and verified the shear strength data of granite weathered soil under different hydraulic paths well, and then theoretically explained the evolution law of the shear strength of granite weathering soil under the change of saturation.

Sign in / Sign up

Export Citation Format

Share Document