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Study on rock strength characteristic by point load test WANG Ruihong 1a，JIANG Yuzhou2b,GUO Jinlong3c,TANG Tiancai4d 1Key Laboratory of Geological Hazards on Three Gorges Reservoir Area，China Three Gorges University，Ministry of Education，Yichang，Hubei 443002，China; 2Key Laboratory of Geotechnical Mechanics and Engineering of the Ministry of Water Resources，Yangtze River Scientific Research Institute，Wuhan，Hubei 430010，China 3China Three Gorges University,Yichang，Hubei ，China 4China Three Gorges University,Yichang，Hubei ，China a43604258@qq.com , bjiangyuzhou5586@163.com, c125317331@qq.com, d444136942@qq.com Key words: Rock specimen; Mechanical test; Point load; Uniaxial compressive strength Abstract：Test point load test requires relatively small load, its instrument is portable, it can be easily applied to on-site testing,which may pave the way for the development of the fieldstrength of rock mechanics test, widely promoted in engineering construction, has a large space for development
Introduction The mechanical strength of rock is an important parameter for rock engineering designing, constructing, its accuracy directly affects the security and stability of the construction and operation, as well as the economic rationality of construction[1-5].
Fig.1 SD-1 Point load instrument author emprical formula Broch & Frankln Rc=29.07 Is（50） International Society for Rock Mechanics Rc=（20~25）Is（50） Chengdu College of Geology Rc=（18~19）Is（50）(minor axis) Rc=23.7Is（50）(macroaxis) Northeast Institute of Technology Rc=65+17.4 Is（50） Second survey and Design Institute of Railways Rc=22.819Is（50）0.745 2003,Quane and Russel sterosome Rc =24.4Is50 weak rock Rc =3.86（Is50）2+5.65Is50 In 2004Tsiambaos and Sabatakakis Rc =7.3（Is50）1.71 Rc =23Is50 In 2005 Fener Rc =9.08Is50+39.32 In 2009 Sabatakakis Point load <2Mpa Rc =13Is50 Point load 2~5Mpa Rc =24Is50 Point load >5Mpa Rc =28Is50 S.Kahraman ·O.Gunaydin weak rock ：Rc =8.20Is+36.43 metamorphic rock：Rc =18.45Is-13.63 sedimentary rock ：Rc =29.77Is-51.49 《Test procedures of physical and mechanical properties of rocks》 Rc=22.77 Is（50） 《Standard for engineering classification of rock mass》GB50218-94 Rc=22.82Is（50）0.75 Rock test specification for Railway Engineering(TB 10115-98) Rc=24.3382Is
The shape and dimensions of the sample, lithology and structure factors directly affect the Rc and Is(50) the relationship.

Especially, a crack phenomenon like hot tearing involves an interaction between stress and metallurgical properties.
In this paper, we studied the relationship between hot tearing and thermal stress considering metallurgical properties.
Macro stress is associated with mechanical constrains as like rigid core and mold.
The new hot tearing predictor is expressed by the linear combination of the stress factors and metallurgical factors as follows )()( mfCsfCH m s += (1) Where f(s) and f(m) are the functions of stress and metallurgical variables, respectively.
Table 1 The ratings of resistance to hot cracking and influence properties on the ratings α (µm/m· k) Composition (Wt %) Material Ratings Liquid Temp.

This research aims to determine the strength of the product, in this case, the stress, strain, and safety factors.
Where the desired final results are von Mises stress, deformation, and safety factor.
Haruyama, “Analysis of three-layer gasket performance affected by flange surface,” EUREKA: Physics and Engineering, no. 4, pp. 57–66, Jul. 2022, doi: 10.21303/2461-4262.2022.002290
Watiniasih, “Identification Plastic Properties of Spot Welded Joints Using the Instrumented Indentation Technique,” IOP Conf Ser Mater Sci Eng, vol. 811, no. 1, 2020, doi: 10.1088/1757-899X/811/1/012020
Karohika, “Indentation Size Effect of the Vickers Indentation to Improve the Accuracy of Inverse Materials Properties Modelling Based on Hardness Value,” in IOP Conference Series: Earth and Environmental Science, 2019. doi: 10.1088/1755-1315/248/1/012009

The mechanical stability of nanostructures depends on the surrounding medium.
The interface between the liquid and the surface is the decisive factor for the influence of the media.
The similar average collapse values from ethanol to 1-butanol (Figure 3a) indicate that the change in electric permittivity from 25 (ethanol) to 18 (butanol) does not affect the mechanical strength of the structures.
Thus, an adhesion failure of the polysilicon on the silicon oxy-nitride is unlikely as it would be expected to depend on the dielectric property of the media.
As the initial crack lowers the overall stability considerably by providing a stress concentration point, it directly affects the mechanical stability of the line structures.

This research focuses on the effects of using both types of fly ashes on mechanical properties of geopolymer.
Starting off as by-products, but once combined with silicate solution or an alkaline hydroxide, they become useful geopolymer materials.The class and source of fly ash will affect geopolymerization reaction, dissolution behaviour, reactivity, and final physical and mechanical properties of the final products.
Addition of calcium compounds as a fly ash substitute improved mechanical properties in the ambient temperature-cured samples while weakening those properties in the elevated temperature-cured samples[3] Improving properties of geopolymer materials without relying on any materials other than the two fly ashes means that we can eliminate the need of additonal mixers, and truly and effectively utilize the residual fly ash.
The phases, positively affecting the compressive strength, can be raised using hydration without relying on heat to accelerate the reaction.
Temuujin, A. van Riessen, R.Williams, Influence of calcium compounds on the mechanical properties of fly ash geopolymer pastes, Journal of Hazardous Materials. 167 (2009) 82–88

Taguchi approach is an efficient and effective experimental method in which a response variable can be optimized, given various control and noise factors, using fewer experiments than a factorial design.
Taguchi’s optimization analysis indicates that the factors level, its significance to influence the surface roughness and flank wear for the machining processes[4].
The factors which affect tool life are depth of cut, feed rate and cutting speed.
Krathikeyan,Assessment of factors influencing surface roughness on the machining of glass –reinforced polymer composites, Journal of Materials and Design, 27, pp.862-871(2006)
Sustarsic, The use of the Taguchi approach ro determine the influence of injection –moldingparameters on the properties of green parts, Journal of achievement in Materials and Manufacturing Engineering,15, 2006

The recrystallization process has also influenced by many factors, such as the holding time, initial grain size, and metal purity [5].
Generally, the recrystallization process will be followed by grain growth and the changes in mechanical properties and texture [5].
Basori, Effect of Deformation and Annealing Temperature on the Microstructures and Mechanical Properties of Cu-32%Zn Brass, J.
Sofyan, Effects of Manganese on the Microstructures, Mechanical Properties and Deformation Characteristics of Cu-29Zn Alloy, Mat.
Wang, Effects of Annealing Temperature and Al Content on Microstructures and Properties of Al-Brass, Procedia Engineering, Vol. 27, 2012, pp. 1823-1828

Rao, Rheological Properties of Aloe Vera (Aloe barbadensis Miller) Juice Concentrates, Journal of Food Process Engineering. 37(2014)375-386
Villa, The influence of Aloe vera gel incorporation on the physicochemical and mechanical properties of banana starch‐chitosan edible films. 
Gaidi, Impact of Sodium Tripolyphosphate on the Rheological Properties of Dams Sediments and Friction Factor during Hydraulic Dredging of Dams.
Freitas, The role played by the aging of aloe vera on its drag reduction properties in turbulent flows. 
Patil, A comprehensive overview of functional and rheological properties of aloe vera and its application in foods. 

In general, ferrites have a polycrystalline structure and are made up of iron oxide as their main constituent with good mechanical properties and black or grey color in appearance.
Manipulation of different processing factors, such as composition, particle size, sintering temperature, heating rate, milling duration, etc. can lead to substantial variations in grain size and determine the performance of the material [7].
Bouamer, Magnetic, optical, structural and thermal properties of copper ferrite nanostructured synthesized by mechanical alloying, Micro Nano Lett. 16 (2021) 251-256
Mertiny, Magnetic Filler Polymer Composites —Morphology Characterization and Experimental and Stochastic Finite Element Analyses of Mechanical Properties, Polymer (Basel) 15 (2023) 2897
Kim, Local probing of eddy current correlated with magnetic properties, Appl.

Mechanical properties of the ECAP processed samples were compared based on hardness measurement.
There are many studies focused on the enhancement of mechanical properties of the Al-Mg alloys [5] [6] [7] [8] [9].
The study focuses on the effect of the number of ECAP passes and ECAP die on the microstructure evolution and mechanical properties.
Jafarian, Microstructure and mechanical properties variations of pure aluminum subjected to one pass of ECAP-Conform process, Mater.
Horita, Plastic flow, structure and mechanical properties in pure Al deformed by twist extrusion, Mater.