3D study of the vibrational behaviour of lithic flint blades DOI Creative Commons
Rostand Tayong Boumda, Tatsuki Fushimi, Ole Grøn

et al.

Results in Engineering, Journal Year: 2023, Volume and Issue: 20, P. 101569 - 101569

Published: Nov. 8, 2023

Stone Age sites are well known to often contain many lithic flint blades and flakes, which may provide important information about early European cultures their environment. Understanding the mechanical behaviour of represents an problem for scientists in general archaeologists particular. In this study, structural is studied. Ten specimens with different geometric shapes (tilted, curved, bumping surfaces) were studied tested. Their natural frequencies, damping ratios, mode (that how specimen deforms under any external excitation) estimated using two models: analytical model that accounts specimen's curvature a 3D Finite Element (FE) method. Advanced experimental methods, including ultrasound techniques, used measure properties specimens. The set-up was built around laser vibrometer measured displacement. predictions compared data validate effectiveness. A good agreement observed between models real data. It particularly despite complicated geometries, still follow structured pattern dynamic response. presented study supports use acoustic methods as effective tool characterize detect submerged prehistoric materials. This work contributes characterization

Language: Английский

Thermal treatment effects on rock fracture behaviour under three loading modes: A comparative analysis of granite and mudstone DOI
Abdel Kareem Alzo’ubi, Mahmoud Alneasan, Farid Ibrahim

et al.

Engineering Failure Analysis, Journal Year: 2024, Volume and Issue: 159, P. 108092 - 108092

Published: Feb. 15, 2024

Language: Английский

Citations

11
Damage evolution and failure characteristics of red sandstone with prefabricated crack under coupled dry–wet cycle-fatigue loading DOI

Han Tan,

Jiangteng Li,

Zhanming Shi

et al.

International Journal of Fatigue, Journal Year: 2023, Volume and Issue: 175, P. 107751 - 107751

Published: June 7, 2023

Language: Английский

Citations

19
Study on Mechanical Properties and Microstructure of Basalt Fiber-Modified Red Clay DOI Open Access
Yu Song,

Yukun Geng,

Shuaishuai Dong

et al.

Sustainability, Journal Year: 2023, Volume and Issue: 15(5), P. 4411 - 4411

Published: March 1, 2023

The effects of basalt fiber incorporation on the mechanical properties red clay soils were investigated. Through direct shear test, unconfined compressive strength and microstructure curves stress–strain fiber-modified obtained under different rates soil dry density conditions. results showed that: (1) significantly increased after fiber; (2) increase was greatest at 0.3% incorporation, which optimum level; (3) damage form changed, incorporated with changed from brittle to ductile damage; (4) microscopic electron microscope pictures that, appropriate amount conditions, bond particles a fiber‒soil column. When subjected external forces, discrete columns interact each other an approximate three-dimensional network, acts restrain displacement deformation particles, is main reason for improved soil. experimental research improvement can provide theoretical basis engineering practice help environmentally friendly efficient method road base treatment in engineering.

Language: Английский

Citations

16
A comparison between conventional and generalized fracture criteria to predict fracture parameters in clay rich rocks (Mudstone) under temperature effect DOI
Mahmoud Alneasan, Abdel Kareem Alzo’ubi, Farid Ibrahim

et al.

Construction and Building Materials, Journal Year: 2024, Volume and Issue: 416, P. 135168 - 135168

Published: Jan. 28, 2024

Language: Английский

Citations

5
Experimental Study on Mechanical Properties and Deterioration Mechanism of Red Sandstone from the Panjiatuo Landslide under Action of Acidic Drying−Wetting Cycles DOI Creative Commons

Ganping Zhang,

Lunan Wang, Zhenning Liu

et al.

Applied Sciences, Journal Year: 2023, Volume and Issue: 13(10), P. 5955 - 5955

Published: May 12, 2023

Due to frequent water level fluctuations and complex hydrochemical environments, rock slopes in reservoir areas progressively deteriorate become unstable. This study investigated the coupling effect of drying−wetting cycles acidic solutions on physical mechanical properties, strain field evolution, failure mode, micro-mechanism red sandstone using a series laboratory experiments (wave velocity tests, uniaxial compression digital image correlation method, scanning electron microscopy, X-ray diffraction). The results showed that with increasing cycles, mass, P-wave velocity, elastic modulus, compressive strength decreased monotonically, while absorption apparent localization band increased. Moreover, mode transitioned gradually from tensile shear or tensile-shear composite failure. decrease solution pH values aggravated changes parameters contributed an increase secondary cracks occurrence behavior. In addition, accelerated worsening microstructure dissolution minerals, resulting loose structure well-developed pores fissures. These provide favorable explanation for property deterioration subjected cycles.

Language: Английский

Citations

12
Experimental analysis and modeling study of the coupled elastoplastic damage model for sandy mudstone DOI

Mingtao Hu,

Weiya Xu, Huanling Wang

et al.

Bulletin of Engineering Geology and the Environment, Journal Year: 2025, Volume and Issue: 84(5)

Published: April 28, 2025

Language: Английский

Citations

0
Development of a standard firebrand accumulation temperature curve for residential wildfire protection system DOI Creative Commons
P. Cantor, M.R.T. Arruda, João P. Firmo

et al.

Results in Engineering, Journal Year: 2023, Volume and Issue: 17, P. 100935 - 100935

Published: Feb. 2, 2023

Climate change and severe heat waves pose a challenge as wildfires spread rapidly in wildland urban interface areas are difficult for firefighters to control extinguish. Therefore, one of the main factors fire cause residential fires is firebrands, which according previous studies can be transported even by wind kilometres. At this moment, there no standard curve simulate thermal effects firebrand accumulation exterior surfaces dwellings, order provide any fireproof design solution. This paper presents new firebrands contact with due indirect action wildfire. An experimental campaign was conducted, different type geometries were burned controlled conditions until they reached pyrolysis state. The tests also performed (1.3 m/s) better simulated their behaviour. temperature transfer measured using test setup metal plates thermocouples. Using data collected from numerous tests, it possible calculate maximum characteristic temperature, calculated 95% confidence interval. curve, proposed simple fitting procedure minimum least square method. aimed used protection systems dwellings located against projection natural

Language: Английский

Citations

8
Extensive experimental investigation on the effect of thermal treatment and lateral pressure on the shear behavior of intact mudstone DOI Creative Commons
Mahmoud Alneasan, Abdel Kareem Alzo’ubi

Scientific Reports, Journal Year: 2023, Volume and Issue: 13(1)

Published: April 26, 2023

The coupling environment of temperature (T) and lateral pressure at great depths promotes intact rocks to shear failure, posing a serious threat underground engineering. Temperature effect on behaviour is particular importance due the possible mineralogical alterations in mineral composition, especially clay-rich such as mudstone that has affinity for water. Accordingly, thermal treatment was investigated, this study, using Short Core Compression (SSC) method. Three temperatures RT, 250 500 °C, four pressures 0.0, 0.5, 2.0, 4.0 MPa were adopted. Numerical experimental observations showed resulting fractures SCC samples are by increasing pressure, failure promoted. Compared with other rock types granite sandstone, properties have only one positive trend increase up T from RT mode II fracture toughness, peak friction angle, cohesion increased about 15 47%, 4.9%, 47.7%, respectively. bilinear Mohr-Coulomb criterion can be used model strength before after treatment.

Language: Английский

Citations

6
Deformation and failure mechanism of surrounding rock mass in a large-scale underground powerhouse under high in-situ stress DOI Creative Commons
Meng Wang, Anchi Shi, Haibo Li

et al.

Results in Engineering, Journal Year: 2023, Volume and Issue: 21, P. 101638 - 101638

Published: Dec. 18, 2023

The surrounding rock mass stability of a large-scale underground powerhouse is the key issue among construction process. This paper takes left bank Baihetan Hydropower Station as case study, which subjected to high in-situ stress and complex geological conditions. Site monitoring, field survey numerical simulation were conducted study deformation failure mechanisms mass. Main patterns identified, analyzed, countermeasures proposed. Results indicate that there are two failure, stress-dominated type structure-dominated type. Deformation at different locations mainly influenced by structure. Since direction in situ maximum principal gently inclines upstream side intersects with axis large angle, compressive concentrated spandrel downstream sidewall foot during excavation. concentration results spalling, fracture shotcrete cracking, belonging timely systematic support prestressed bolt. At sidewalls, unloading main pattern anchor cable right time recommended. occurs arch under impact shear zones, grouting supplementary effective measures. can provide references for mechanism analysis dynamic optimization powerhouse.

Language: Английский

Citations

5
Fracture mechanism and constitutive model considering post-peak plastic deformation of marble under thermal–mechanical action DOI Creative Commons
Meiben Gao, Tianbin Li, Liang Zhang

et al.

Geomechanics and Geophysics for Geo-Energy and Geo-Resources, Journal Year: 2024, Volume and Issue: 10(1)

Published: Oct. 16, 2024

Temperature plays an important impact on rock mechanical properties. In this paper, the properties, fracture mechanism and constitutive model of marble under 20–120 °C 15 MPa are studied. The results show deformation can be divided into four stages: compaction, linear elasticity, crack propagation post-peak failure. Stress–strain curve is not obviously affected by temperature. Macroscopic characteristics change from shear failure to tensile mixed with temperature increasing. With increase temperature, strength tends decrease, indicating that has a weakening effect marble, there temperature-sensitive areas 20–60 sub-sensitive 60–120 °C. elastic modulus decreases Poisson's ratio increases increasing energy evolution law different basically same, which shows before initiation, dissipation less, after damage yielding occurs, quickly. in process mainly used for initiation-connection-penetration, as well plastic caused friction slip cracks, have good characteristics. statistical based three-parameter Weibull distribution function effectively reflect strain softening. at related its internal moisture excitation. water stimulated absorb attach original relatively dry interface, role lubrication. relative motion resistance between solid particles or surfaces decreases, leads initiation consumption reduction, changes specific surface rocks weakens marble. provide theoretical basis predicting evaluating long-term stability safety surrounding underground deep engineering complex environment high ground geo-stress.

Language: Английский

Citations

1