Perpendicular Shear Research Articles

On electromagnetic turbulence and transport in STEP

In this work, we present first-of-their-kind nonlinear local gyrokinetic (GK) simulations of electromagnetic turbulence at mid-radius in the burning plasma phase of the conceptual high-β, reactor-scale, tight-aspect-ratio tokamak Spherical Tokamak for Energy Production (STEP). A prior linear analysis in Kennedy et al (2023 Nucl. Fusion 63 126061) reveals the presence of unstable hybrid kinetic ballooning modes (KBMs), where inclusion of the compressional magnetic field fluctuation, δB∥ , is crucial, and subdominant microtearing modes (MTMs) are found at binormal scales approaching the ion-Larmor radius. Local nonlinear GK simulations on the selected surface in the central core region suggest that hybrid KBMs can drive large turbulent transport, and that there is negligible turbulent transport from subdominant MTMs when hybrid KBMs are artificially suppressed (through the omission of δB∥ ). Nonlinear simulations that include perpendicular equilibrium flow shear can saturate at lower fluxes that are more consistent with the available sources in STEP. This analysis suggests that hybrid KBMs could play an important role in setting the turbulent transport in STEP, and possible mechanisms to mitigate turbulent transport are discussed. Increasing the safety factor or the pressure gradient strongly reduces turbulent transport from hybrid KBMs in the cases considered here. Challenges of simulating electromagnetic turbulence in this high-β regime are highlighted. In particular the observation of radially extended turbulent structures in the absence of equilibrium flow shear motivates future advanced global GK simulations that include δB∥ .

Experimental investigation of layering pattern arrangements on mechanical, swilling and water absorption behavior of flax/coir fiber based bio-epoxy composites

As natural fibres are recyclable and biodegradable, they are essential to the creation of ecologically sound composite materials. When compared to synthetic fibres, they have benefits including less environmental impact, superior mechanical qualities, and a lightweight nature. Gaining knowledge about and improving the usage of natural fibres in composites can result in environmentally friendly solutions that have a lower carbon footprint and more durability across a range of uses. The present research concentrates on the manufacture of hybridized bio-composites with eco-friendly epoxy as the matrix phase and flax as well as coir fibre mats as reinforcing agents. The hybridized composites of flax (F) and coir (C) fibres were created using a low-cost manual lay-up approach, accompanied by a hot press containing various stacking sequences. The materials' static characteristics, like inter-laminar shear strengths (ILSS) as well as hardness, were investigated. Physical parameters like water absorption and swelling thickness were also investigated. The experimental findings demonstrate that whenever the layering pattern was changed, bio-composites displayed small variations in strength properties. The FFFF sample had the greatest ILSS result of 7.69 MPa. Short beam breakdowns feature such as perpendicular inter-laminar shear fractures, micro buckling, and fibre breakage have also been observed. Although there were some advantages in the mechanical properties of bio-composites over eco-friendly epoxy, there were no significant consequences for modifying the toughness characteristics of a fibre sheet's cross-ply. This might be attributed to the low interaction of coir and flax strands, in addition to the hybrid composite specimens' poor interfacial bonding and strength. In comparison to their hybrid equivalents, pure fibre or non-hybrid materials demonstrated greater resilience to water uptake as well as thickness swelling.

Observations of near-inertial internal wave amplification and enhanced mixing after surface reflection

The overreflection process of near-inertial internal waves (NIWs) has been theoretically predicted for several decades; however, to the best of our knowledge, this phenomenon has never been comprehensively investigated in real ocean scenarios. Based on the buoy observations collected several days after the passage of Typhoon Lekima in the Yellow Sea, a NIW surface overreflection event is clearly captured. The observed NIWs undergo nearly total reflection meridionally but are amplified zonally after reflection by approximately 20% in amplitude and 56% in vertically integrated horizontal kinetic energy. Ray tracing analysis indicates that the NIW was generated in the wake of Typhoon Lekima in the area north of the Shandong Peninsula and may propagated to the buoy station as coastal-trapped internal Kelvin waves. A simulation using a slab mixed layer model suggests that local wind work was insufficient to generate the amplified NIWs. The temporal evolution of near-inertial energy also implies that the intensified near-inertial waves cannot be attributed to the spontaneous generation resulting from unbalanced flows or the parametric subharmonic instability of M2 internal tides during the reflection period. We found a high temporal correlation between the zonal NIW enhancement and the duration of a meridional lens-type shear flow after reflection, which is consistent with the Stern’s overreflection theory (Stern, 1977) that perpendicular background shear flow can feed energy to the incident NIWs. This indicates that the enhanced NIW may be stimulated by the near-surface reflection and the rotation effect plays a crucial role in the NIWs overreflection process in the real ocean. Furthermore, enhanced instability are found between the ocean surface and the upper thermocline after reflection. This study provides observational evidence that the background field could inject energy into the near-inertial band through NIW overreflection process, and may shed some light on understanding upper ocean mixing caused by NIW reflection.

Effect of cyclic shear stress ratio on cyclic behavior of clay under multidirectional shear loading

In offshore engineering, soft clay foundations supporting infrastructure are subjected to significant multidirectional cyclic shear stresses due to earthquake or storm loads. To explore the undrained multidirectional cyclic behavior of foundation clays under critical loading conditions, a series of tests were conducted using a variable-direction dynamic cyclic shear system. By controlling the amplitude ratio (η) of two mutually perpendicular shear stresses in the horizontal plane, both unidirectional and multidirectional cyclic shear stress paths were achieved. The shear strength, stiffness, and pore water pressure are presented and discussed by considering the effects of η and cyclic stress ratio (CSR). The results suggest that the increase of CSR and η accelerates the cyclic failure, stiffness degradation, and pore water pressure accumulation of the clay specimens. An η-independent cyclic strength curve is established by normalizing the CSR to 0.755 η . Although η hardly affects the shear modulus in the x direction (G x) during the first cycle and at failure, it affects the parameter (χ) governing the shape of the stiffness degradation curve. Additionally, a model is proposed for predicting the evolution of normalized residual pore water pressure with respect to the number of cycles, wherein the parameter d remains unaffected by CSR and η.

Structural behavior of stainless steel anchor channels embedded in concrete under perpendicular and longitudinal shear

Stainless steel anchor channels with channel bolts (SSAC-CBs) have been chosen as alternatives to conventional carbon steel anchor channels to enhance corrosion resistance, ductility, and load-bearing capacity. This study evaluated the shear performance of SSAC-CBs embedded in concrete members under perpendicular and longitudinal shear loads using static monotonic tests. The failure modes and shear capacities of the specimens were compared with those obtained by finite element analysis (FEA) models established using ABAQUS. Concrete edge breakout failure accompanying the channel flexural yielding and channel bolt fracture dominated in the SSAC-CBs under perpendicular shear. The load–displacement curves for perpendicular shear exhibited four salient stages: initial linear elasticity, slippage, strain hardening, and damage and failure. Under longitudinal shear, the SSAC-CB specimens exhibited a failure of the serrations in the contact area between the serrated channel bolt head and channel lips and slip failure between the hook-type channel bolt and channel lips. In addition, the numerical analysis results indicated that the load-bearing capacities, initial elastic stiffnesses, and failure modes obtained through the FEA models were consistent with the test results. Furthermore, theoretical formulas were proposed for the shear capacity for SSAC-CBs under perpendicular and longitudinal shear. The research outcomes provide valuable guidance for the design and application of SSAC-CBs in engineering.

Tensor decomposition for modified quasi-linear viscoelastic models: Towards a fully non-linear theory

We discuss the decomposition of the tensorial relaxation function for isotropic and transversely isotropic (TI) modified quasi-linear viscoelastic (MQLV) models. We show how to formulate the constitutive equation using a convenient decomposition of the relaxation tensor into scalar components and tensorial bases. We show that the bases must be symmetrically additive, i.e., they must sum up to the symmetric fourth-order identity tensor. This is a fundamental property both for isotropic and anisotropic bases that ensures the constitutive equation is consistent with the elastic limit. We provide two robust methods to obtain such bases. Furthermore, we show that, in the TI case, the bases are naturally deformation-dependent for deformation modes that induce rotation or stretching of the fibres. Therefore, the MQLV framework allows to capture the non-linear phenomenon of strain-dependent relaxation, which has always been a criticised limitation of the original quasi-linear viscoelastic theory. We illustrate this intrinsic non-linear feature, unique to the MQLV model, with two examples (uni-axial extension and perpendicular shear).

A Teleoperated Robotic System-Assisted Percutaneous Transiliac-Transsacral Screw Fixation Technique.

Transiliac-transsacral screw fixation is challenging in clinical practice as the screws need to break through six layers of cortical bone. Transiliac-transsacral screws provide a longer lever arm to withstand the perpendicular vertical shear forces. However, the screw channel is so long that a minor discrepancy can lead to iatrogenic neurovascular injuries. The development of medical robots has improved the precision of surgery. The present protocol describes how to use a new teleoperated robotic system to execute transiliac-transacral screw fixation. The Robot was operated remotely to position the entry point and adjust the orientation of the sleeve. The screw positions were evaluated using postoperative computed tomography (CT). All the screws were safely implanted, as confirmed using intraoperative fluoroscopy. Postoperative CT confirmed that all the screws were in the cancellous bone. This system combines the doctor's initiative with the Robot's stability. The remote control of this procedure is possible. Robot-assisted surgery has a higher position-retention capacity compared with conventional methods. In contrast to active robotic systems, surgeons have full control over the operation. The robot system is fully compatible with operating room systems and does not require additional equipment.

Cyclic response of sandy subsoil layer under traffic-induced principal stress rotations: Application of bidirectional simple shear apparatus

Cyclic response of soil layers under moving wheels includes Principal Stress Rotation (PSR), which evidently cannot be simulated with a conventional cyclic uniaxial triaxial test. The hollow cylinder apparatus (HCA) has been used as a solution to assign a more realistic stress path, taking into account the continuous PSR. However, the effective horizontal stress is also harmonically changed due to the cyclic increase in the effective vertical stress – under a horizontally constrained condition with zero lateral strain – and is inevitably overlooked in the HCA. In this study, the application of the Bidirectional Direct Simple Shear (BDSS) apparatus is scrutinized so that not only are the shear and, of course, normal stress components considered, but the expected increase in the effective horizontal stress is subsequently assigned as well. Besides, the effects of an initial shear stress component superimposed either parallel or perpendicular to the direction of moving wheels are studied. A series of cyclic simple shear experiments employing a heart-shaped stress path is conducted on a sandy soil for up to 10,000 cycles to determine the permanent deformation. An empirical model is also fitted for calculating the residual strains (i.e., vertical and shear strains). The results show the role of cyclic shear and normal stress components intensifying both shear and vertical strains. Moreover, parallel and perpendicular static shear stress components can effortlessly escalate deformation, particularly the shear strains. BDSS apparatus can be a reasonable alternative to HCA in terms of convenience in the sample preparation, real zero lateral strain condition, and assignment of static shear stress components.

Effects of the parallel flow shear on the ITG-driven turbulent transport in tokamak plasmas

The impact of the parallel flow shear on the tokamak plasma stability and turbulent transport driven by the ion temperature gradient (ITG) modes is analyzed by means of local gyrokinetic numerical analyses. It is shown that the parallel flow shear increases the ITG growth rate in the linear regime, and induces a broadening and shift of the radial spectrum. Then, the different effects of the finite parallel shear on the ITG turbulence characteristics are deeply analyzed in the nonlinear regime. These studies highlight that a reduction of the thermal-ion turbulent heat flux is induced by a complex mechanism involving the nonlinear generation of an enhanced zonal flow activity. Indeed, the turbulent sources of the zonal flows are increased by the introduction of the finite parallel flow shear in the system, beneficially acting on the saturation level of the ITG turbulence. The study has been carried out for the Waltz standard case below the critical threshold of the destabilization of the parallel velocity gradient instability, and then generalized to a selected pulse of a recent JET scenario with substantial toroidal rotation in the edge plasma region. It is, thus, suggested that the investigated complex mechanism triggered by the finite parallel flow shear reducing the ITG turbulent heat fluxes could be complementary to the well-established perpendicular flow shear in a region with sufficiently large plasma toroidal rotation.

Ship’s Wake on a Finite Water Depth in the Presence of a Shear Flow

The ship’s wake in the presence of a shear flow of constant vorticity at a finite water depth is investigated by expanding the Whitham-Lighthill kinematic theory. It has been established that the structure of a wave ship wake radically depends on Froude number Fr (in terms of water depth) and especially on the critical Froude number Frcr, which depends on the magnitude and direction of the shear flow. At its subcritical values Fr<Frcr two types of waves are presented: long transverse and short divergent waves inside the wedge area with an angle depending on Fr For the supercritical range Fr>Frcr only divergent waves are presented inside the wake region. Critical Froude number Frcr is variable and mostly depends on collinear with the ship path component of the shear flow: it decreases with the unidirectional shear flow and increases on the counter shear current. The wedge angle of the ship wake expands with an increase in the unidirectional shear flow and narrows in the oncoming flow in the subcritical mode of the ship’s motion Fr<Frcr. Wake angle decreased with Froude number for Fr>Frcr and only divergent waves with the crests almost collinear with ship path are finally presented in the narrow ship wake. For a critical value of the Froude number Fr=Frcr, the ship’s wake has a total wedge angle of 180° with waves directed parallel to the ship’s motion. The presence of a shear flow crossing the path of the ship gives a strong asymmetry to the wake. An increase in the perpendicular shear flow leads to an increase in the difference between the angles of the wake arms.

Simultaneous strength and ductility enhancements of high thermal conductive Ag7.5Cu alloy by selective laser melting

High electrical and thermal conductive metals (HETCM) play a key role in smart electronics, green energy, modern communications and healthcare, however, typical HETCM (e.g., Ag, Au, Cu) usually have relatively low mechanical strength, hindering further applications. Selective laser melting (SLM) is a potentially transformative manufacturing technology that is expected to address the issue. Ag is the metal with the highest thermal conductivity, which induces microscale grain refinement, but also leads to high internal stresses by SLM. Here, we select Ag7.5Cu alloy as an example to demonstrate that multi-scale (micro/meso/macro) synergies can take advantage of high thermal conductivity and internal stresses to effectively strengthen Ag alloy. The mimicry of metal-hardened structures (e.g., large-angle boundary) is extended to the mesoscale by controlling the laser energy density and laser scanning strategy to manipulate the macroscale internal stress intensity and mesoscale internal stress direction, respectively, to form mesoscale large-angle "grains", resulting in multiple mutual perpendicular shear bands during fracture. The presented approach achieved a significant enhancement of yield strength (+ 145%) and ductility (+ 28%) without post-treatment. The results not only break the strength-ductility trade-off of conventional SLM alloys, but also demonstrate a multi-scale synergistic enhancement strategy that exploits high thermal conductivity and internal stresses.

Influence of wood species and adhesive type on the performance of multilaminated plywood

The quality of plywood depends on factors such as the forest species and the adhesive used in their production, and understanding the interferences of these factors in the final properties of the plywood is of fundamental importance. The study aimed to develop multilayer plywood with two forest species and two types of adhesive and to evaluate the influences of these factors (forest species and adhesive) on the physical and mechanical properties of the plywood. The panels were produced with wood veneers of parica and pine with two types of adhesives, urea-formaldehyde and phenol-formaldehyde, with a weight of 150 g.m2. Then, each set was pressed for 10 min under a specific pressure of 0.98 MPa at a temperature of 150 °C. Three panels were produced for each type of veneer and adhesive, totaling four treatments. The plywood was evaluated for physical properties (moisture content, bulk density, and water absorption) and mechanical properties (parallel and perpendicular static bending strength and shear strength). The results showed that the forest species had a greater influence on physical and mechanical properties, with the best results being observed for plywood produced with pine and PF adhesive. The specific mass of the panels should be considered as it positively influenced the mechanical properties and negatively impacted water absorption. The PCA was used to reduce the dimensionality of the data from 9 dependent variables to 2 main components, explaining 76.70% of the total variance of the data. The multivariate analyzes of the differentiated independent factors showed that both the species and the adhesive affected as properties of the plywood and both independent variables must be taken into account in the production of the plywood. It is concluded that the porosity and specific mass of the paricá veneers contributed to a greater penetration of the adhesives, resulting in lower physical and mechanical properties than the pine veneers. However, in general, it is concluded that the plywoods produced can be used for internal and external applications. However, it is not indicated for structural purposes as it did not meet the requirements of the NBR 31.000.001/2:2001.

Experimental and numerical investigation on incremental laser shock clinching for joining three sheets of copper/aluminum/stainless steel

A novel method to make a round end rectangular joint whose total length is much larger than the diameter of the laser spot, named as incremental laser shock clinching, was proposed in this paper. Experimental and numerical investigation was conducted to verify the feasibility for joining three sheets of copper/aluminum/stainless steel. The transverse section and the appearance of the joint were explored to determine the spacer height and the forming strategy. The shape evolution of interlock was discussed by observing sectional images. To describe the material flow characteristics in the forming process, a series of typical points were traced. The mechanical properties of the joints relating to the load directions and clamping ways were studied by tensile shear tests. The results show that fine joints with smooth surface morphology and uniform thickness can be obtained under the larger spacer height and multi-passformingstrategy. Simulated results agree well with the experimental results, which implies that the finite element model can be effectively used to analyze the process. During deformation, most material flows along the transverse direction to form undercuts, meanwhile flows slightly towards the laser spot moving direction. What’s more, the maximum load in the perpendicular shear test is larger than that in the parallel shear test. Two failure modes are observed when the copper foil and pre-slotted sheet are clamped on one side and only one failure mode is found when the copper foil is clamped alone.

Effects of leg fatigue due to exhaustive stair climbing on gait biomechanics while walking up a 10° incline – Implications for evacuation and work safety

This biomechanics study explored stride length (SL), stride duration (SDN), the peak of gait ground reaction forces (GRFspeak), required coefficient of friction (RCOFpeak), joints’ angle (anglepeak), angular velocity (angvelx peak), angular acceleration (angaccx peak), minimum angle (anglemin) of foot, and muscle electromyography (EMG) during the dominant leg stance phase (SP) following an exhaustive stair ascent for evacuation. Data were collected by a three-dimensional motion capture system synchronized with EMG and force plate when walking upwards on a 10° inclined walkway.The significantly (p ≤ .05) decreased EMG median frequencies of tibialis anterior during early (ES) and late stance (LS) phases, and vastus lateralis muscles during LS are the evidence of leg local muscle fatigue (LMF). The perpendicular and longitudinal shear GRFspeaks were significantly reduced during ES (p ≤ .05) and LS (p ≤ .01), respectively. The post-fatigue SP, SL, and SDN were significantly (p < .05) shorter. Specially, the foot anglemins, ankle anglepeaks, and relevant angvelx peaks, and angaccx peaks significantly (p ≤ .05) decreased in post-fatigue trials. The post-fatigue RCOFpeaks were found significantly (p ≤ .01) lower during LS phase. Thus, whole body exhaustion and leg LMF constrained the gait kinetics and kinematics when walking upwards indicating a cautious gait associated with the risks of falls, accidents, which can hinder the process of evacuation and work safety on slopes.

Natural radioactivity and geochemical aspects of radioactive mineralisation in El Sela, South Eastern Desert, Egypt

ABSTRACT The natural radioactivity data revealed that eU reached up to 157.4, 1625 and 178 ppm in microgranite and dolerite dikes as well as japer vein, respectively, whereas the two-mica granite possesses the higher eTh-contents up to 53.8 ppm. Mineralogically, the two-mica granite is enriched in thorite, brockite and uranothorite, whereas uraninite and coffinite are recorded in dolerite, and the latter one is recorded in microgranite, bostonite and jasper. Primary uranium minerals as uraninite and coffinite could be a source for uranium enrichment and the formation of secondary uranium mineralisation. Uranium mobilisation was active towards the two perpendicular shear zones having NNW-SSE and ENE-WSW rejuvenated trends. Successive hydrothermal alterations play their role in the formation of uranium ore deposits to be trapped in post-granitic dikes.

Determination of the Shear Modulus of Pine Wood with the Arcan Test and Digital Image Correlation.

Arcan shear tests with digital image correlation were used to evaluate the shear modulus and shear stress–strain diagrams in the plane defined by two principal axes of the material orthotropy. Two different orientation of the grain direction as compared to the direction of the shear force in specimens were considered: perpendicular and parallel shear. Two different ways were used to obtain the elastic properties based on the digital image correlation (DIC) results from the full-field measurement and from the virtual strain gauges with the linear strains: perpendicular to each other and directed at the angle of π/4 to the shearing load. In addition, the own continuum structural model for the failure analysis in the experimental tests was used. Constitutive relationships of the model were established in the framework of the mathematical multi-surface elastoplasticity for the plane stress state. The numerical simulations done by the finite element program after implementation of the model demonstrated the failure mechanisms from the experimental tests.

Kinematics of the Ship’s Wake in the Presence of a Shear Flow

We present the kinematic model of the ship wake in the presence of horizontal subsurface current linearly varying with the depth of water. An extension of the Whitham–Lighthill theory for calm water is developed. It has been established that the structure of ship waves under the action of a shear flow can radically differ from the classical Kelvin ship wake model. Co propagating ship and shear current lead to increasing the total wedge angle up to full one 180° and decreases for the counter shear current. At relatively large unidirectional values of the shear current, cusp waves in the vicinity of the wedge boundary are represented by transverse waves and, conversely, by diverging waves directed almost perpendicular to the ship track for the opposite shear current. The presence of a shear flow crossing the direction of the ship’s movement gives a strong asymmetry of the wake. An increase in the perpendicular shear flow leads to an increase in the difference between the angles of the wake arms. The limiting value of the shear current corresponds to one or both arms angles equal to 90°. Transverse and divergent edge waves for this limiting case coincide.

Slip of low-angle tilt grain boundary (110) in FCC metals at perpendicular shear

Grain boundaries (GBs) make a significant contribution into the kinetics of plastic deformation of both polycrystalline and nanocrystalline metals. Among others, motion of GBs is an important phenomenon, which has to be taken into account in the consideration of the thermo-mechanical response of poly- and nanocrystals. In this work, we study motion of low-angle tilt GBs and the accompanying relaxation of shear stresses in the case, when the shear is applied perpendicular to GB. Using the molecular dynamics (MD) simulations, we consider bicrystals made of aluminum, copper and nickel as FCC metals with different stacking fault energies. MD data are used for construction and verification of a GB motion model, which is based on the previously proposed equation of motion of a solitary dislocation in a single crystal. Within this model, a low-angle tilt GB is presented as a wall of periodically located perfect edge dislocations. The main driving factors are the external shear stress and the local stress distribution due to the plastic relaxation in the trace of each dislocation creating an area of partially relaxed stresses behind the shifted GB. These factors define the average GB velocity during the main stage of motion, while dislocation-dislocation interactions between the walls and inside each wall define details of the motion, such as the curvature of GBs and their mutual acceleration at the late stage of interaction of two approaching opposite GBs.

Development of an H-shaped shear key for mutually perpendicular precast shear walls

Prefabricated reinforced concrete (PC) shear walls are widely used because of their convenience of construction. Diverse forms of wall joints for assembling precast shear walls were studied in the recent decade. However, during the assembly of mutually perpendicular precast shear walls, it is difficult to satisfy joint strength requirements. In this study, an H-shaped Shear Key (HSK) with welding connections was proposed for the connection of mutually perpendicular precast shear walls. Quasi-static cyclic loadings were conducted to test the seismic properties of HSK specimens with different welding configurations. The strength, energy dissipation capacity and fatigue properties of specimens were compared. Image measurement was adopted to measure the damage patterns and crack dimensions. The test results validated the effectiveness of the HSK specimens and appropriate configurations of HSKs are recommended for practical engineering applications.

Effects of tectonically induced fabrics on geomechanical properties of rocks, NW Pakistan

The Chakdara Granitic Gneisses (CGG) of the Indian plate and Kamila Amphibolite of the Kohistan Island Arc (KIA) along the Main Mantle Thrust (MMT) in Shigo Kas, Talash Dir Lower, indicate that tectonically induced foliations and lineations strongly affected the geomechanical properties of these rocks. The earlier S1 crenulated cleavages are well preserved in the microlithon of a well-developed ENE-WSW trending S2 crenulation cleavage. The pervasive S2 foliations, D2 fold axes, and L22 lineations are induced by NNW-SSE horizontal bulk shortening. The core samples obtained parallel and perpendicular to the main ENE-WSW trending S2 and L22 have higher and lower uniaxial compressive strength (UCS) values, respectively. The UCS and uniaxial tensile strength (UTS) average values of four core samples obtained parallel and perpendicular to the main S2 are 51.8 MPa and 12.21 MPa versus 45.65 MPa and 12.45 MPa, respectively. Core samples from the weakly foliated S-2 specimen shows little variation in the UCS and UTS values. The variation in the UCS values in the core samples cut perpendicular and parallel to the main tectonic fabric has been controlled by micro-shear zones at the contact zones of crenulated and crenulation cleavages and sigmoidal mica fish. The UCS values are higher in the core samples parallel to the pervasive S2 and L22 because the parallel shear on the sigmoidal crenulated cleavages in microlithon of the S2 and S2 mica fish counterbalance the parallel external applied load. However, the UCS values decrease in the core samples that were cut perpendicular to the pervasive S2 and L22 because the perpendicular shear on the sigmoidal crenulated cleavages in microlithon of the S2 and S2 mica fish enhances the external applied load, which lead to the failure of core samples.