31 results about "Damage zone" patented technology

The invention belongs to the technical field of rock wall crane beam construction, and particularly relates to an excavation method for brittle rock body rock wall crane beam forming under the high ground stress condition. According to the excavation method for forming the fragile rock wall crane beam under the high ground stress condition, excavation parameters are provided in real time by establishing a refined finite element model of rock mass near an excavation area, and in an expected range, a primary damage area and a secondary damage area in a protective layer are controlled within the expected range, so that the contour of the rock wall crane beam is drawn, and the rock wall crane beam is formed. The rock wall crane beam is formed, so that the excavation difficulty of the rock wall crane beam is reduced, and the forming quality of the rock wall crane beam is guaranteed.

The present application relates to a kind of potential rock burst pit depth quantitative estimation method considering structural plane and excavation disturbance effect, obtain the initial maximum principal stress and rock uniaxial compressive strength of the region to be estimated, preliminary evaluation whether it has the potential to occur rock burst;Surrounding rock is estimated to estimate the scope of excavation damage zone by sound wave test;According to the sound wave test data, the disturbance factor at different depths is estimated;According to the change characteristics of disturbance factor, the height damage zone and weak damage zone range of surrounding rock in excavation damage zone are estimated;Estimate the potential rock burst pit depth of surrounding rock.The present application not only considers rock strength and stress condition, but also considers the influence of structural plane and excavation disturbance on potential rock burst pit depth, uses high-precision, low-cost and convenient sound wave test technology and a small amount of rock indoor strength test can be realized, with greater innovation, practicality, economy and feasibility.

The invention relates to an underground engineering fire hazard hazard detection and damage evaluation method, and belongs to the technical field of underground engineering safety monitoring. The method is based on the principle of muon transmission imaging, a three-dimensional monitoring network is constructed by arranging ground and drilling hole detection arrays, data such as muon flux, energy and incident angles are collected, coal rock density distribution is inverted, and a density situation map is generated. A weighted comprehensive discrimination model is established by analyzing carbon content change and combining fault, fracture and permeability characteristics, and a fire abnormal area is identified. Furthermore, damage variables are defined according to density changes before and after combustion, a fire area is divided into a core damage area, a transition damage area and an edge damage area, and quantitative and graded evaluation of the damage degree is achieved. The device has the characteristics of non-invasion, deep penetration and high resolution, is suitable for fire dynamic monitoring and damage evaluation of underground engineering such as coal mines and tunnels, and provides a reliable basis for fire early warning and post-disaster repair.

The application relates to a kind of high-efficiency construction methods for rapidly repairing cement concrete bridge deck with UHPC, and belongs to the technical field of bridge repair, comprising the following steps: step one: damage assessment, judging damage condition according to bridge deck damage range and depth; step two: surface treatment, dust removal, decontamination and cleaning of boundary crack area not connected with the center of damaged area using tools to make the boundary crack area connected with the center of damaged area, forming a complete repair surface; step three: data recording of cleaned damage range and depth; step four: UHPC material preparation, preparing raw materials and making according to the data recorded in step three; step five: pouring the prepared UHPC material into the center of damaged area, and thin rod is needed to guide the boundary crack area; step six: after repair is completed, covering the damaged area with film for wet curing, which can improve construction efficiency, relieve traffic pressure, shorten repair period and reduce maintenance cost.

The invention provides a cargo damage assessment method and device, electronic equipment and a storage medium, and relates to the technical field of logistics, and the method comprises the steps: carrying out the multi-dimensional information collection of a to-be-assessed cargo, obtaining multi-modal data, inputting the multi-modal data into a multi-scale feature fusion model, and obtaining a multi-scale feature fusion model; extracting feature maps of different scales based on the multi-modal data through a multi-scale feature fusion model, and fusing the feature maps of different scales; and inputting the fused feature map into a damage assessment model to obtain a damage assessment result of the to-be-assessed cargo. According to the method, firstly, feature maps of different scales are extracted based on collected multi-modal data through a multi-scale fusion model, damaged areas of different sizes can be captured through the feature maps of different scales, and then the fused feature maps obtained based on the feature maps of different scales are input into a damage evaluation model. Therefore, the damage assessment model can assess the damaged areas of different sizes, thereby improving the accuracy of cargo damage assessment.

The invention discloses a rock mass mechanical parameter determination method and system for a rock slope blasting excavation damage area, particularly relates to the technical field of rock mass engineering stability evaluation, and is used for solving the problem of misalignment of parameter characterization caused by neglecting a damage area rock bridge and fracture zone composite structure in the prior art. The method comprises the following steps: arranging a point load test in a damage area and identifying non-unimodal distribution data; combining fracture catalog data, fusing penetrability fracture density segmentation capability and a dominant inclination angle direction failure effect to generate a collaborative isolation parameter, and dividing a residual rock bridge and fracture fracture zone spatial distribution mode according to the collaborative isolation parameter; accurately classifying the intensity data into two types of subsets based on space mapping; and finally, macro-mechanical parameters are generated through weighted fusion of the area proportion and the double-source strength statistical value, the rock mass strength prediction precision of the blasting damage area is remarkably improved, and a reliable basis is provided for slope stability analysis and support design.

The invention discloses a chamber excavation surrounding rock failure area simulation method and related equipment, and relates to the field of geotechnical engineering stability evaluation.The method comprises the steps that an underground chamber excavation process is simulated through an underground chamber initial model without setting support measures, a plastic zone range is obtained, and principal stress information of a corresponding unit of a failure area is extracted; calculating the damage degree of the surrounding rock based on the surrounding rock stress state; performing zoning operation on the damage area according to the surrounding rock damage degree to obtain refined zoning information; on the basis of a triaxial compression test, rock mechanical parameters related to the residual strength of the surrounding rock under different damage degrees are obtained; assigning values to different partitions with different damage degrees according to the rock mechanical parameters related to the residual strength; and excavation numerical simulation is conducted again to obtain a new plastic zone range and main stress distribution, and final partition assignment and refined simulation are completed. According to the method, the authenticity, engineering adaptability and reliability of numerical simulation are improved, and the method has clear technical progress and engineering practical value.

The application discloses a test method for studying the connection mechanism of hydraulic fractures and high-angle shear type fractures, and belongs to the technical field of indoor test of rock mass hydraulic fracturing. The test method for studying the connection mechanism of hydraulic fractures and high-angle shear type fractures preforms a through fracture at the side of a sample close to the top, performs high-temperature thermal shock treatment on the inner side of the through fracture, thereby forming a gradient damage zone, and processes a perforation upward in the middle of the bottom surface of the sample; the treated sample is placed in an experimental device, and a plurality of acoustic emission probes are pasted on the surface of the sample; a surrounding pressure and an axial pressure are sequentially applied by using a staged loading mode, then high-pressure water fracturing is continuously carried out in the perforation at a constant rate, and the fracture pressure and the corresponding flow rate are recorded when the sample is broken; the hydraulic fracturing process is analyzed according to the flow-pressure curve obtained by the test and the information collected by the acoustic emission probes, and the connection law of the hydraulic fracturing fractures and the through fractures is obtained by combining the CT three-dimensional reconstruction technology after the test.

The invention discloses a wedge-shaped broaching groove blasting scheme design method, and belongs to the technical field of mining and tunnel blasting. The method comprises the following steps: firstly, determining the radius of a crushing area and the radius of a crack area of the single-hole columnar cartridge bag; setting an initial vertical blast hole position in the cutting roadway; by taking the initial blast hole as a reference, arranging wedge-shaped blast holes by adopting a rotary replication method, so that the crushing areas of the adjacent blast holes are adjacent, the fracture areas are overlapped, and an angle difference is determined; parallel wedge-shaped blast holes are supplemented in an uncovered area of the middle fissure area; finally, a row of blast holes are formed in the center line and the two sides of the roadway respectively, and the damage area covers the designed width of the roadway. The quantitative hole distribution model is established based on the damage partition radius, precise connection is achieved, and the blasting efficiency and the forming quality are improved.

A method for producing a structured glass disk is provided that includes the steps of: providing a glass disk having a thickness of at most 400 μm; directing and focusing a laser beam onto the glass disk such that the laser beam produces an elongated focus within the glass disk with an intensity sufficient to produce damage within the glass disk along the elongated focus; moving the laser beam and the glass disk relative to one another to insert damage zones along a ring-shaped path so that a workpiece is defined in the glass disk with the ring-shaped path encompassing the workpiece and with the workpiece remaining connected to the glass disc; exposing the glass disk to an etchant so that the etchant intrudes into the damage zones; and chemically toughening the glass disk with the workpiece.

A damage assessment module operating on a computer system automatically evaluates a roof, estimating damage to the roof by analyzing a point cloud of a roof. The damage assessment module identifies individual shingles from the point cloud and detects potentially damaged areas on each of the shingles. The damage assessment module then maps the potentially damaged areas of each shingle back to the point cloud to determine which areas of the roof are damaged. Based on the estimation, the damage assessment module generates a report on the roof damage.

This invention relates to a method for detecting fire hazards and assessing damage in underground engineering projects, belonging to the field of underground engineering safety monitoring technology. Based on the principle of muon transmission imaging, this method constructs a three-dimensional monitoring network by deploying ground and borehole detection arrays to collect data such as muon flux, energy, and incident angle, inverting the density distribution of coal and rock to generate a density trend map. By analyzing changes in carbon content and combining fault, fracture, and permeability characteristics, a weighted comprehensive discrimination model is established to identify abnormal fire areas. Furthermore, based on density changes before and after combustion, damage variables are defined, dividing the fire area into core damage zone, transitional damage zone, and edge damage zone, achieving quantitative and graded assessment of the degree of damage. This invention features non-invasiveness, deep penetration, and high resolution, making it suitable for dynamic fire monitoring and damage assessment in underground engineering projects such as coal mines and tunnels, providing a reliable basis for fire early warning and post-disaster repair.

This invention provides a method and system for predicting the damage evolution of concrete lining in tunnel fires, relating to the field of computer technology. The method includes: acquiring geometric feature data of the tunnel, fire image data, and high-temperature performance data of the lining concrete; constructing a thermal flow field based on the geometric feature data and fire image data to obtain a three-dimensional transient temperature field; calculating the internal forces of each section based on the three-dimensional transient temperature field and the high-temperature performance data of the material to obtain the real-time internal force state of each section of the lining; determining damage initiation based on the real-time internal force state of each section of the lining to obtain the spatiotemporal distribution of the initial damage zone; performing damage-internal force coupled evolution based on the spatiotemporal distribution of the initial damage zone to obtain the damage evolution path; and generating a safety situation map based on the damage evolution path to obtain a spatiotemporal evolution map of structural risk. This invention significantly improves the accuracy and reliability of predicting the damage evolution process and final safety state of tunnel concrete lining under fire conditions.

The present application relates to the technical field of precision optical mold manufacturing, and particularly relates to a splicing method of a nickel mold for a micro-prism type reflective film, which first determines a welding damage zone width a through laser welding. Then, when splicing in the 0-degree direction, the cutting position is positioned at a position of moving a distance a / 2 along the 0-degree line of the 0-degree cone outward, so as to avoid the welding damage zone from affecting the effective cone. When splicing in the 90-degree direction, according to the bottom side length L of the effective cone and the distance b of the nearest effective cone from the 90-degree damage edge, the welding zone is determined to be alternately arranged by the combination of invalid cones and effective cones with different areas on both sides, so as to maximize the retroreflective efficiency. Then, in the 0-degree and 90-degree directions, cutting is respectively performed by using a precision cutting device, and after alignment on a splicing platform, welding is performed by using a precision laser welding device. The technical problem of poor retroreflective efficiency and overall uniformity in the splicing area in the prior art is solved.

It is disclosed a computer-implemented method for modelling a reservoir comprising fault zones, comprising: - Obtaining an initial model of the reservoir (100) and ground data (200), - Implementing (300) at least one set of fault zones generation in the initial model, comprising receiving input parameters (310), and, based on the received ground data and input parameters: o generating at least one core zone (322) of a fault zone, and a damage zone extending around the core zone, and o Generating a plurality of fault segments (324) within the damage zone.

The application provides a method and system for measuring the damage depth of a silicon wafer after wire sawing, which comprises: determining the transition zone between the outer surface of the silicon wafer and the damage zone; the upper boundary line and the lower boundary line of the transition zone are parallel to each other, and the upper boundary line and the lower boundary line are determined according to the wire mark direction and the position information of the damage point; constructing a boundary line parallel to the upper boundary line and bisecting the transition zone; constructing a damage termination line parallel to the boundary line through the Nth damage point in the damage zone; and measuring the distance between the boundary line and the damage termination line as the damage depth of the silicon wafer. By defining the transition zone and the standards of the boundary line and the damage termination line, the application improves the boundary ambiguity and data error problems in the damage depth measurement, improves the measurement accuracy and repeatability, reduces the measurement instability caused by accidental errors, and is suitable for a wide range of types.

The invention relates to a method for repairing a part (10) made of a ceramic matrix composite material, the part having a damaged zone, the method comprising: - a step of machining away at least the damaged zone so as to obtain a recessed repair zone (12); - a step of placing, in the recessed repair zone (12), a repair material (13) comprising at least one ply (15) of composite material preimpregnated with a ceramic matrix precursor; - a step of compacting the one or more plies (15) of composite material preimpregnated with the ceramic matrix precursor in order to increase a fiber volume content; and - a sintering step for consolidating a bond between the repair material (13) and the composite part (10).

The application discloses a kind of underground space surrounding rock excavation damage zone test method, belong to rock mass damage test technical field, comprising: first, different depth rock sampling and do ultrasonic test, determine rock sample attenuation characteristic and wave velocity;Then determine the comprehensive damage index range of different damage grade rock samples according to this;Then, in the process of excavation, sensor is laid out to collect ultrasonic and acoustic emission data;Then, an initial calculation model is constructed, and a surrounding rock three-dimensional wave velocity model is obtained by using the collected data inversion;Finally, the damage grade is determined according to the comprehensive damage index and marked in the model, and the damage zone test is realized.The method establishes the mapping relationship between damage degree and wave velocity change, proposes the threshold value of comprehensive damage index range in different partitions, realizes quantitative and hierarchical classification, and also inverts a three-dimensional wave velocity model based on test and monitoring data, realizes three-dimensional presentation and hierarchical labeling of damage zone.

The invention relates to a fire resistant glazing (100), comprising at least one first glass pane (101) and a second glass pane (102), which are parallel to one another and mutually spaced, and a fire resistant layer (103) provided between the two glass panes (101, 102). A safety device (1) having an impact element (13) for impacting against the glass pane (101) is provided on at least one glass pane (101) of the two glass panes (101, 102), and the safety device (1) is provided with a temperature-controlled triggering mechanism (6) for the impact element (13), said triggering mechanism being designed to cause the impact element (13) to impact against the glass pane (101) in case of fire in such a way that a local damaged region is produced in the glass pane (101), said damaged region causing the glass pane (101) to shatter.

The invention belongs to the technical field of building structure design, and particularly relates to a design method of a high-strength reinforced concrete beam-column joint capable of improving anti-seismic property, which limits and adjusts the hooping rate of stirrups in a core area of the beam-column joint to be greater than 1.359% through matching use of ultra-high performance concrete, common concrete and high-strength steel bars; the change of a node failure mode from core area shear failure to beam end bending failure is realized, and the node ductility is obviously improved; the joint axial pressure ratio is smaller than or equal to 0.2, so that the displacement ductility and the energy dissipation capacity are prevented from being remarkably reduced due to the too high axial pressure ratio; meanwhile, the distance between one end, close to the column, of the unbonded section area of the unbonded area and the surface of the column is larger than or equal to 0.5 times of the beam height, the length is 1.0-1.5 times of the beam height, and the damage area is prevented from being located in the core area; a gradual change area is arranged to prevent stress sudden change; the connecting pipe is arranged, so that the ultra-high performance concrete and the common concrete work in a highly cooperative manner; and a shear bearing capacity calculation formula is innovated.

This invention belongs to the field of engineering construction technology and relates to a design and construction method for an anchorage support structure for high-temperature and high-stress tunnels. The method includes the following steps: establishing a coupled model of the high-temperature and high-stress tunnel; determining the distribution law of surrounding rock damage and the distribution law of crack propagation; dividing the surrounding rock damage into zones; and constructing a composite anchorage support structure. This invention establishes a coupled model of the high-temperature and high-stress tunnel by coupling the temperature field, seepage field, stress field, and damage field. The distribution law of surrounding rock damage and the distribution law of crack propagation are obtained through this model. The surrounding rock damage is then divided into zones. Finally, the corresponding anchorage support structure is selected based on the surrounding rock damage and crack propagation in different zones. The anchorage support structures in different zones together constitute a composite anchorage support structure, fully considering the effects of the high-gradient temperature field and the thermal-water-mechanical coupling effect on the support, thus avoiding the increase of the surrounding rock damage zone.

The application discloses a kind of based on stress balance's surrounding rock plastic damage zone analytical prediction method, belong to tunnel engineering technical field, including the following steps: obtaining initial plastic zone boundary;Based on plastic zone area correction model and lower than plastic stress part elastic stress distribution is invariable, obtain the elastic load summation of surrounding rock stress before adjustment lower than yield stress part and the elastic load summation of elastic zone after stress adjustment is equal when radius tends to infinity, and the elastic load summation of surrounding rock stress before adjustment higher than yield stress part and the summation of load of plastic zone after stress adjustment is equal;Based on stress balance principle, obtain the radius of surrounding rock plastic zone;Based on the radius of surrounding rock plastic zone and polar coordinate plotting, obtain the range and form distribution characteristics of tunnel surrounding rock plastic zone;The application solves the problem of insufficient accuracy of tunnel engineering surrounding rock plastic zone solution in stress prominent area.

A segmented water pressure test device is arranged in a water injection drill hole 10 of an actually measured working face top plate two-zone and a bottom plate damage zone and comprises a first hole packer 20, a second hole packer 30 and an expansion connecting pipe 40, the expansion connecting pipe 40 is communicated with an expansion cavity of the first hole packer 20 and an expansion inner cavity of the second hole packer 30, the second hole packer is arranged on the side close to a hole opening 11 of the water injection drill hole 10, and the expansion inner cavity of the second hole packer 30 is communicated with the expansion inner cavity of the expansion connecting pipe 40. The interval space between the first hole packer and the second hole packer is a segmented hydrostatic test section S. The second hole packer 30 is connected with a test water injection pipeline 12 and an expansion pressure pipeline 13. The utility model has the beneficial effects that the double plugging devices are adopted to carry out segmented water pressure test on a single water injection drill hole, test data of the whole segment of the water injection drill hole can be obtained, test positions can be flexibly selected, the number of the water injection drill holes and test equipment are reduced, the test cost is obviously saved, the working efficiency and the equipment utilization rate are improved, and the production cost is reduced. And the test data is enriched.

The application discloses a roadway supporting precise intervention method, which utilizes a roadway surrounding rock fracture zone and stress testing technology to monitor the fracture zone and stress state of the roadway surrounding rock, judges the roadway surrounding rock stress peak position and the fracture zone boundary position according to the monitoring data, determines the surrounding rock fracture zone range index R f , the surrounding rock damage zone range index R d , the surrounding rock stress rising zone range index R u , the surrounding rock stress falling zone range index R l , and thus determines the roadway supporting parameters, and determines the intervention time of the supporting measures according to the roadway surrounding rock fracture zone development speed index t f and the stress field development speed index t s , accurately determines the supporting intervention scheme according to the roadway surrounding rock stability state, fully plays the supporting efficiency of the supporting measures, significantly improves the supporting efficiency, reduces the supporting cost, realizes the coupling effect and collaborative control of the supporting structure and the surrounding rock, and guarantees the long-term stability of the deep roadway.

This invention provides a method and system for refined characterization of blasting damage zones and calculation of surrounding rock loads. The method includes: acquiring working parameters related to tunnel blasting excavation; constructing a numerical model based on these parameters; solving the numerical model to obtain the strain increment of the tunnel surrounding rock under blasting loads; inputting the strain increment into a strain rate-related dual-scalar tensile-compressive damage constitutive model to obtain tensile damage factors and compressive-shear damage factors; establishing damage evolution laws related to strain rate for the tensile strain tensor and compressive-shear strain tensor respectively in the dual-scalar tensile-compressive damage constitutive model, independently characterizing the tensile damage mechanism and the compressive-shear damage mechanism; evaluating the damage zoning of the tunnel surrounding rock based on the tensile damage factors and compressive-shear damage factors to obtain tensile damage zones, compressive-shear damage zones, and refined zoning; and determining the surrounding rock load based on the tensile damage zones and compressive-shear damage zones. This invention achieves refined characterization of blasting damage, thereby enabling accurate determination of the surrounding rock load.

A damage assessment module operating on a computer system automatically evaluates a property, estimating damage to the property by analyzing a point cloud of a property. The damage assessment module identifies individual point clusters or segments from the point cloud and detects potentially damaged areas of the property surface by identifying outlier points in the point clusters. The damage assessment module may be used to determine the financial cost of the damage and / or determine whether the property should be replaced or repaired. In addition to eliminating the need for an estimator to visit the property in person, the damage assessment module improves the consistency and accuracy associated with estimating damage to a property.

This invention discloses a simulation platform and a dynamic evaluation method for support effects in composite roof roadways, specifically relating to the field of digital simulation technology. It addresses the problem of delayed support effect evaluation caused by insufficient fusion of multi-source monitoring data in existing digital twin systems. By acquiring multi-source monitoring data on microseismic, stress, and deformation, the invention identifies key bearing layers in the composite roof, delineates potential damage zones within these layers, and determines the effective anchorage range based on support parameters. It analyzes the spatial competition between these two layers, predefines multiple typical support failure modes based on this relationship and the rock structure, and constructs a damage evolution trajectory for each mode that reflects the collaborative evolution law of multi-source data. Real-time monitoring data is dynamically matched with each trajectory to determine the target support failure mode and its evolution stage corresponding to the current damage state. Based on this, the control effect of the current support scheme is evaluated, and dynamic early warning information is generated, achieving a mechanistic and forward-looking dynamic evaluation of support effects.

The invention discloses a test method for researching a connection mechanism of a hydraulic fracture and a high-angle shear type fracture, and belongs to the technical field of rock hydraulic fracturing indoor tests. According to the test method for studying the connection mechanism of the hydraulic fracture and the high-angle shear type fracture, a through fracture is prefabricated in the position, close to the top, of the side face of a sample, high-temperature thermal detonation treatment is conducted on the inner side of the through fracture, so that a gradient damage zone is formed, and a perforation is machined upwards in the center of the bottom face of the sample; placing the treated sample in an experimental device, and pasting a plurality of acoustic emission probes on the surface of the sample; confining pressure and axial pressure are sequentially applied in a staged loading mode, then high-pressure water injection fracturing is continuously carried out in the perforation at a constant rate, and when the sample is fractured, the fracture pressure and the corresponding flow are recorded; according to the flow-pressure curve obtained through the test, the acoustic emission probe collects information, the hydraulic fracturing process is analyzed, and in combination with the CT three-dimensional reconstruction technology after the test, the communication rule of the hydraulic fracturing crack and the through crack is obtained.

This invention discloses an abrasive waterjet rock-breaking method with a secondary impact effect and composite abrasive particles. The composite abrasive consists of a core, an intermediate layer, and an outer shell. The method uses a nozzle to accelerate the jet and impact the rock. First, the composite abrasive particles as a whole undergo an initial impact, forming a damaged zone. Subsequently, the impact load causes the outer shell and intermediate layers of the particles to fracture as designed, releasing the core particles. The core particles, driven by the high-speed water flow, precisely impact the aforementioned damaged zone a second time. The intermediate layer has a lower body strength than the outer shell and core, and its interfacial bonding strength with adjacent layers is precisely designed to ensure stability during transport, while reliably failing during the first impact to release the core. This invention achieves sequential energy utilization through a synergistic "impact-release" mechanism, significantly improving the rock-breaking efficiency of hard rock and the utilization rate of abrasive kinetic energy.

The invention relates to the technical field of optical fiber processing, in particular to an optical fiber coating layer stripping opening forming method which comprises the following steps: S1, laser chain scission of a coating layer: irradiating a passivation layer through laser in the circumferential direction of an optical fiber so as to break a main chain chemical bond of the passivation layer at the irradiation position, and forming an annular damage belt; s2, mechanical scraping thinning of the coating layer: scraping the coating layer at the annular damage belt through mechanical cutting until the coating layer is away from the surface of the cladding by a preset distance; s3, laser finishing of the coating layer: breaking a main chain chemical bond of the residual coating layer on the surface of the cladding at the annular damage belt through laser; s4, stripping the coating layer and cleaning the residual coating layer: stripping the coating layer on one side of the annular damage belt from the cladding layer, and reserving the coating layer on the other side of the annular damage belt; and then cleaning the residual coating layer at the annular destroying belt to obtain the stripping opening. According to the method disclosed by the invention, a molecular-level flat stripping opening can be obtained.