Search

Tensile bond strength is one of the most significant properties for structural silicone sealants used in the glass curtain walls. During the service process, aging of the silicone sealants shall be involved in comprehensive actions of environment factors, e.g. temperature, humidity, and ultraviolet light etc. In this study, artificial accelerated aging test was conducted to make clear the development of tensile bond strength, Shore hardness and elongation. The test results show that: (i) the specimens under damp-heat test have more degeneration than specimens under humidity-freeze test; (ii) the environment of high temperature and high humidity leads to the change of tensile bond, Shore hardness, elongation, and results in interfacial failure of samples.

Alumina ceramics are widely used in the demanding high temperature applications in which the high temperature elastic moduli (EHT) is a key property for their reliability and safety. In this paper, the elastic modulus of alumina was determined by dynamic method (impulse excitation technique) and static tests (three-point bending test and four-point bending test). For the static tests, the relative method was applied to determine the accurate deflection measurement in the heating furnace. The measured results revealed that the modulus of alumina slowly decreased from RT to 1000 °C and rapidly decreased with the increasing temperatures from 1000 °C to 1300°C. The EHT evaluated by dynamic method were higher than that tested by static tests with the reason of that impulse excitation technique only applied small forces onto a sample such that defects activity is negligible. Also the resonant frequencies couldn’t be measured easily at high temperature, because the vibration signal emitted by the sample was weak. The static approaches combined with relative method were beyond the limit to high temperatures, and they can be also used to evaluate the ultra-high temperature modulus.

The spherical indentation combined with acoustic emission was used to evaluate the local strength of glass, which is a nondestructive testing approach. However, stress time effect on the local strength of glass during spherical indentation has not been studied before. In the present work, stress time effect was investigated by examining the local strength of unstrengthened and strengthened glass at different loading rates. It is discovered that the local strength of glass increased greatly with the loading rate, which confirmed the time dependence of the fracture on glass. As a typical brittle material, the discreteness of strength date of glass measured by spherical indentation was also analyzed to evaluate the strength of glass correctly.

The purpose of this paper is to study the durability and performance of photovoltaic glass components in salt spray environments. So it can be founed that a reasonable solution to increase the life of PV glass and to ensure the continuity of its performance. The PVB film was used for the comparison and performance analysis of the salt spray treatment of salt water at one week and two weeks. The PVB film was tested for the light transmission performance and other mechanical properties changes of PVB film. It was shown that the strength of the PV module sample after one week of salt spray treatment is 26.48508MPa, and the strength of the sample after two weeks of salt spray treatment of the PV module is 13.35496MPa. The direct sunlight transmittance ratio of A groups (300 ~ 2500nm) is 94.50. Direct sunlight transmission ratio of B groups (300 ~ 2500nm) is 92.30. The results show that the light transmission performance of the PV module after salt spray cycle is reduced by 2.3%, and the strength is obviously decreased by 49.57%.

In order to overcome the limitations of common methods for measuring elastic modulus of the ultra-thin glass，a novel method is proposed for measuring the elastic modulus of the ultra-thin glass by cantilever beam vibration method．The measurement principle，apparatus，and manipulation were introduced. In this method, the measured ultra-thin glass is generated in the form of a cantilever beam, and the cantilever beam can be vibrated for a short time when transient excitation is applied. The natural frequency of the cantilever beam can be used to calculate the elastic modulus of the ultra-thin glass material. A series of ultra-thin glass samples with different thickness were tested in this work, the measured values are consistent with that given . The effect of beam length/thickness ratio on determination of elastic modulus of materials by means of cantilever method was analyzed, the result shows that the influence of the ratio can be neglected if the beam length is equal to or more than 10 times of the beam thickness.

Surface stress measurement is the key factor of the quality control for tempered glass. The nondestructive test of glass surface stress is based on the character of stress birefringence in glass. The basic principle of the measurement and test methods are introduced. The optical waveguide effect of tin-diffused layers plays a key role in prevalent surface stress measurements. The apparatus are compared for optimizing the testing devices. A portable digitalized surface stress meter based on optical waveguide effect is developed, which can work in severe optical conditions and reduce operation difficulty. The calibration record shows good linearity.

Interfacial bond strength is one of the vital mechanical properties of adhesives. The cross-bonded method, which is widely used to measure the interfacial tensile and shear bond strength simultaneously, has attracted extensive attention. An improved cross-bonded method is presented in this study in order to promote the accuracy and reliability of the testing results. The ergo 9900 glue, E-7 glue, AB glue and 502 glue were measured in this study. Compared with the original method, the results of the improved cross-bonded method show that: (i) the coefficient of variation of the interfacial bond strength decreased significantly; (ii) the interfacial shear bond strength of the adhesives is closer to its true value.

To explore the effects of preparation process on the mechanical properties of fiber reinforced tubes in radial direction, the closed ring method was applied to assess the elastic modulus and bending strength of GFRP and CFRP prepared by winding method and pultrusion method, respectively. The results indicate that there are two obvious differences between the winding tube and the pultrusion tube: i) the elastic modulus and bending strength of the winding tube for two materials are larger than that of the pultrusion tube. It should be attributed to the position of materials under stress: the former is the fibers while the latter is the matrix; ii) the failure mode for the winding tube is brittle fracture while elastic-plastic fracture is for the pultrusion tube. Compared with other experimental methods, the results of the closed ring method are accurate and reliable, which is demonstrated to be a potential method to evaluate the mechanical properties of fiber tubes in radial direction rapidly and conveniently.

Because of its excellent optical performance, photo-physical properties, thermal stability, the fused silica is widely used in laser and aerospace industry. Fused silica can be made to the large-aperture lens for high power laser facilities or the windows for detecting devices. In order to meet the applications, the surface shape of the fused silica must be polished to better than 1/3λ(P-V). If the result of stress-birefringence is big, it is hard to control the surface shape. The permanent stress of a large-aperture fused silica was measured with digital stressmeter and analyzed from manufacturing process stand point.The forming reason and the removing way of different types of stresses were also analyzed in this article. The structure stress is the permanent one in all the types, which also affects the result and the morphology of optical homogeneity.

A simple test approach named relative method is developed for determining the thermal expansion coefficient of ceramic coatings. Although ceramic coatings are hardly separated from the substrates, it was evaluated in this work simply by need only the measured thermal expansion coefficient of coated samples and substrates. This novel method was demonstrated to be valid for rectangular beam samples of two types of coating configurations: sandwich coating and around coating. The feasibility of this test method was confirmed by experimental results of SiC coating.

Young’s moduli of coatings in the both perpendicular and horizontal directions were evaluated by the relative method, which are determined via establishing the relationship between the uncoated specimen and the coated specimen, with different coating positions during the loading tests. Compared with other traditional methods, the relative method is much simpler in both sample pretreatment and testing device. The validity and reliability of this method has been demonstrated by the beam specimens with CVD-SiC coatings, which will be applied to establish and improve a simple and reliable evaluation system for the anisotropy of coating modulus.

Synthetic quartz glass is an excellent transmittance material in ultraviolet (UV), visible and near-infrared bands. Homogenization process to synthetic quartz glass optical elements is done in order to make the composition and structure more uniform. The homogenization temperature is above 1800°C. After high-temperature homogenization, the UV transmittance of quartz glass appears a certain extent of decline in the edge partition., After high temperature homogenization process, it is found that the closer the layer to the graphite vessel, the stronger influence on UV transmittance will be. This conclusion is made by comparing the UV transmission of the quartz glass in different layers. Furthermore, the factors affecting the UV transmittance is also analyzed in this article.

The elastic modulus and fracture strength at ultrahigh temperatures over 1500°C is very important for Ultrahigh temperature ceramics (UHTCs), but no available method can be used so far because of the limitation of the testing equipments. In this work, a novel testing equipment was developed to determine the elastic modulus and fracture strength (bending, tensile and shear strength) of ceramics from 1500 °C to 2200 °C. To check the availability and reliability of this equipment, several typical UHTCs including C, C/C fiber woven composite and C/SiC ceramic composite, were used as the testing samples. The results indicate that this new designed testing equipment is a good and feasible for evaluating the ultrahigh temperature mechanical properties of ceramics over 1500 °C in vacuum or in air.

Optical homogeneity of the optical materials directly affects the wavefront quality of the refractive optical system. There are some difficulties of testing large caliber optical materials, four-step method of Fizeau interferometry is a convenient and accurate method for measuring optical homogeneity. The article used the four-step method test the same quartz glass sample in a cavity with different precision and found that the optical homogeneity test results have a larger gap. While this article compared the effect of the fixed cavity surface shape and the changing cavity surface shape on 300 mm diameter quartz glass optical homogeneity test and analyzed the effect of different positions of fixed cavity distortion on optical homogeneity testing.

Although elastic modulus of ceramic coatings at elevated temperature is difficult to measure, it was evaluated in this work simply by impulse excitation tests based on the relative method that need only the measured moduli of coated sample and substrate. This novel method was demonstrated to be valid not only for the single layer coating but also for multilayer coatings.

Temperature and humidity cycles test of photovoltaic glass modules are carried out by different cycling time. The change of transmittance, interface and strength of photovoltaic glass modules are compared by different experiment time. With the increasing of temperature humidity cycle time of photovoltaic glass modules, the light transmittance of influence is more serious, and stress strength of the longest cycle is weakened 32.84% than one cycle. Therefore, the influence of photovoltaic glass modules under different temperatures and humidity conditions is more serious. So it is very necessary to study durability and safety under temperature and humidity cycles of photovoltaic glass, related to power generation efficiency of the photovoltaic glass modules.

Vacuum failure will lead to insulation function failure and increasing huge potential security problems for vacuum glazing, it is necessary to inspect the vacuum degree value of the vacuum glazing in service. In this work, the relationship between the bearing behavior and vacuum degree value of the vacuum glazing was studied by experiment, the experiment results show that the bearing behavior of vacuum glazing showed a greater than 50% reduction after the vacuum degree lose completely in vacuum cavity of the vacuum glazing. One test technique for degradation ratio of vacuum degree of vacuum glazing by photoelastic method was developed in this study. Through linear proportional relationship between support stress spot size and degradation ratio of vacuum degree observed via photoelastic method, vacuum degree completely disappear and stress spot size is 0. So, the ratio R(less than or equal to 1) represent the relative differential pressure between the support stress spot size tested in-situ and the support stress spot size measured in vacuum degree intact environment. The degradation ratio of vacuum degree is (1-R) %. Obtaining qualitative or semi-quantitative assessment of vacuum degree degradation ratio of vacuum glazing through observe support stress spot size with photoelastic apparatus.

Alumina is a typical ceramic material and possesses high strengthand stiffness at both room temperature and high temperature. The split ring methodhad been established to evaluate the elastic modulus and bending strength of aluminatube materials at ambient temperature. However, both equations for modulus andstrength became lightly inapplicable with the increased temperature. For theelastic modulus, it was lack of precise approaches and advices for deformationmeasurement in the heating furnace. For the bending strength, changes of sampledimensions due to thermal expansion would take an effect on the calculatingresults. In this work, several improvements have been taken into account tocalibrate the above deviations. Results revealed that the modulus and strengthregularly decreased from room temperature to 1300 °C and accorded well with other conventional testing methods.It proved the accuracy and reliability of this modified split ring method,which might be used to evaluate other ceramic tube materials at hightemperature.

Aiming at the shortcomings of traditional research method of materials mechanics performance of concrete, this paper presents a new method to test the mechanical properties of concrete material layer body--the relative method. It focuses on the use of relative principle, testing dynamic elastic modulus of concrete damage layer subjected to single salt freezing cyclic, and draw a gradient damage curve of concrete, and then study the damage process of the concrete under the effect of salt solution and the freeze-thaw cycle synergetic factors. The method provides a new way to test body layer mechanical performance of concrete material which the traditional methods can not be directly solved.

The main mechanics behavior character of building silicone sealant is its time dependence£¬which lies in the existence of the interior timepiece or the characteristic time. The creep behaviors were fundamental to evaluating the long-term performance of the building silicone sealant under long-term external loading. A series of creep tests of building silicone sealant were conducted in the laboratory under different combinations of external loads, the characteristics of the creep curve were obtained. In this work, the creep behaviors of building silicone sealant were also investigated under various temperatures at invariable stress. The test measurements show that the creep behavior of building silicone sealant are nonlinear, Nonlinear creep behavior is analyzed by means of the equivalence principle of time-stress, the main creep curve under reference stress was obtained by fitting with the viscoelastic rheological model. So the long-term creep behavior of the building silicone sealant under lower stress can be predicted by short-term creep behavior under higher stress.

Evaluation of the mechanical properties at ultra-high temperatures for ceramic composites is necessary and important for the safety of designing the ceramic components. In this work, a new and novel test method named as local ultra-high temperature together with applied load method (LUHTAL), was developed to determine the tensile, compressive, bending strength and fracture toughness of ceramic composites. The four point bending load was conducted to measure the bending strength and fracture toughness of ceramic composites after the center of the sample was heated up to about 1500-2000°C by oxygen-assisted spray combustion. To check the availability and reliability for this method, typical ceramic materials including ZrB2/SiC and C/SiC fiber reinforced composite coated with Si, were used as the testing samples. It is indicated that this method is good and feasible for evaluating the mechanical properties of the ceramic composite at ultra-high temperatures in air.

The damage experiments of reinforced concrete (RC) samples under synergistic effects of cyclic freeze-thaw, deicing-salt attack, rebar corrosion and bending stress were investigated using a comprehensive experimental method. Synergistic effects of these factors on the damage evolvement of RC were studied by measuring the change of dynamic modulus of concrete, rebar strain and concrete strain. Experimental results showed similar rule in damage evolvement but different damage rate between the normal-strength concrete (C45, the 28-day compressive strength of 52 MPa) and the high-strength concrete (C70, the 28-day compressive strength of 77 MPa). The dynamic modulus of the reinforced concrete degraded with increasing effecting factors.

The Impulse Excitation technique is a nondestructive and very convenient testing method. It could be applied at different circumstances such as high temperatures, low temperatures and controlled humidity. The Impulse Excitation technique is based on the analysis of the vibration of a test sample after it was impulse excited. The elastic properties of a test specimen are related to its mechanical resonance frequency. In this paper, the regular of resonance frequency changed with specimen’s size was discussed. Elastic modulus of glass with different length, width and thickness were measured, and ceramic composite material with small size was tested. The results indicate that the resonance frequency of specimen changed with its size regularly, and the specimen with small size has poor accuracy of elastic modulus measurement.

Due to its outstanding performance and merits, Self-Consolidating Concrete (SCC) has attracted a wide attention from scientists, researchers and engineers all over the world. At present, many research activities have been conducted in developing and evaluating SCC and its related technologies. However, existing performance evaluation methods of are mostly limited in the field of material, while structure performance evaluation methods of SCC are rarely reported. As we all known, the lifetime of the SCC structure is mainly subject to its material, structural and durability performances as a whole. Undoubtedly, it is crucial for us to study and develop a sound structural and durability performance evaluation method to complement the existing material performance evaluation methods. As such, the structural and durability performance evaluation method of SCC was studied in this paper.

Vacuum insulation panel is the one type of the insulation materials. The characteristics of this material are not only low thermal conductivity, good sound insulation, energy efficient, environmental protection but also with no ODS material. However, the inadequate mechanical properties of this material limit its application of insulation in construction . Thus, this research proposed the uses of the connection of structure and function of vacuum insulation panel in construction , and tested against its Sound Insulation Property. new construction sound insulation standards was adopted for evaluating the result of Sound Insulation Property to study the building insulation performance of the vacuum insulation composites

It is significant to explore the fatigue contact damage of bi-layer ceramic composites in order to improve the long-time mechanical reliability of bi-layer structured dental restorations. In this study, Hertz contact test was used to compare the fracture modes and the ability of anti-fatigue damage of zirconia and alumina bi-layer composites, to analyze the effect of loading rate and other factors on the damage mechanisms of bi-layer ceramic composites. Cyclic spherical fatigue loading was put on the bi-layer alumina and zirconia composites with different substrates. The samples were observed by high depth of field stereomicroscope and digital optical microscope after test. The results showed that the fatigue contact damage mode of zirconia bi-layer composite was the porcelain fracture from radial cracks without the damage of zirconia core. The fatigue contact damage mode of alumina bi-layer composite was the alumina core failure from radial cracks as the function of contact load. For both of zirconia and alumina bi-layer samples, the number of cycles to the sample failure as the function of same maximum contact load with high loading rate was obviously smaller than low loading rate. The mechanical properties of the substrate materials had limited effects on the number of cycles to the failure of both zirconia and alumina bi-layer samples from contact-induced radial cracks as maximum contact load with low loading rate. The ability of the zirconia bi-layer composites to resist fatigue damage was much higher than that of the alumina bi-layer composites.

There is no national standard and international standard about nominal module operating temperature (NMOT) test methods for Building Integrated Photovoltaic (BIPV) modules. An in-lab testing method for measuring NMOT of BIPV modules is proposed. Based on the real operation condition of solar cell, the effect of ambient temperature, wind speed and optimal load resistor to operating temperature were analyzed. The surface temperature, interior temperature and back temperature of BIPV module were measured and the NMOT was determined.

In this work, a new and novel test method was developed to determine the impact bending strength of ceramic composites at ultra-high temperature from 1500-2000 °C in air. Three-point impact bending test was carried out through a SiC pressure head with a dynamic force sensor fixed on a slider and movable along a guide rail. The impact load was adjusted by different saving energy and the impact speed was lower than 0.5 m/s. The center of the sample was heated up to about 1500-2000°C by oxygen-assisted spray combustion. An impact load was put on the specimen and the impact force was recorded automatically. The impact bending strength can be calculated from the maximal load and the sample size. To check the availability and reliability for this method, several ceramics including SiC, ZrB2/SiC and C/C fiber reinforced composite without coating, were used as the testing samples. The results indicate that this method is a good and feasible method for evaluating the mechanical properties of the ceramic composite at ultra-high temperatures.

The existence of a temperature difference across a vacuum glazing causes dimensional differences between the hot and cold glass sheets, with associated mechanical stresses and bending. In order to understand the distribution characteristics of the stresses and deformation in vacuum glazing due to temperature difference, in this work, the mechanical models were established and the calculation formula of the shear stress in the edge seal and bending tensile stress on the surface of the two glass sheets of the vacuum glazing were given. A test device was designed and the maximum tensile stresses and deflection of the vacuum glazing with various temperature difference were tested by experimental, it was shown that they are identical between the experiments and the theories.

Mobile robot becomes more and more perfect with people research continuously, obstacle avoidance is one of the most basic function in the process of operation. At present, the robot simulation system is an important tool of researching robot. In this paper, hardware design and software design were done by NSTRSS and real-time dynamic obstacle avoidance simulation of mobile robot is completed successfully. The experimental result shows that the simulation has 3D scene, lively effect and a good operation interface.

Ti3SiC2-Al2O3joint with strong interface has potential high temperature applications because it combines with the merits of hard ceramics and soft ceramics. The safety is strongly dependent on the interfacial bonding strength between Ti3SiC2and Al2O3. In this work, the cross-section method was suggested to evaluate the tensile and shear bonding strength for Ti3SiC2-Al2O3joint from room temperature to 800 °C in air. A novel testing fixture made of SiC was designed and machined to avoid the bending stress at the bonding surface during the testing process. It is indicated that the measured shear bonding strength is usually higher than tensile bonding strength for Ti3SiC2-Al2O3joint. Both the tensile and shear bonding strength are decreased with the increment of testing temperatures. At 800 °C, the tensile and shear bonding strength are declined to be about 43.15% and 45.02% compared with those at room temperature, relatively. The mechanism for the strong interface between Ti3SiC2and Al2O3is also discussed.

A novel hybrid photovoltaic/thermovoltaic solar system (PV/TV) was designed with PV cells combined with heat collector and thermoelectric generator. This PV/TV model can collect heat from the solar panels to reduce its surface temperature, and then to generate electricity by using of temperature difference technology and devices. In this paper, electricity generation performance of PV/TV system between April to October was tested and discussed. The application of this system in photovoltaic building was discussed. The results indicate that overall efficiency of this PV/TV system is higher than that of a pure PV system, and about 5%-15% efficiency increase.

A self-designed testing device for high-temperature elastic modulus was developed based on the principle of acoustical resonance, having great accuracy and repeatability. Experiment was made to test the elastic modulus of two kinds of glass. The experimental data showed that compared with normal glass, Al2O3•SiO2 glass was the 1.2 times the value of elastic modulus of normal glass and had greater stability than normal glass in high temperature. The softening point temperatures of Al2O3•SiO2 glass and normal glass were respectively 600°C and 400°C. The self-designed testing device was able to estimate the property of glass.

This research employs pressureless sintering process to study the impact of different amount of titanium diboride on the performance of silicon carbide-titanium diboride composite. Results show that: no new phase was produced, and the whole process is a solid-phases sintering process. In this experiment, it has the smallest relative density and loss on ignition and porosity, and highest degree of densification of the silicon carbide-titanium diboride composite ceramics sintered body when the titanium diboride content is 50g, and the quality of SiC and TiB2 ratio is 1:1.

In order to understand the carrying capacity and deformation characteristics of vacuum glazing, experimental and theoretical research were carried out on load bearing capacity of four sides supported vacuum glazing, the load-displacement and load-stress curves of the test samples under uniform load were obtained. The experimental result indicated that under the test samples have the same thickness, the capacity of resisting wind load of the vacuum glazing is not so strong as common glass plate. To design methods of the vacuum glazing plate, one of those is to calculate the stresses and the deflection with the equivalent thickness as an integral model. The equivalent thickness coefficient of the vacuum glazing is about 0.85~0.9, and the magnitudes of the equivalent thickness coefficient of the vacuum glazing is decreases with increasing of the glass thickness, but not been influenced by the length and width dimensions of the glass plate. Take into account the influence of long term tensile stresses in vacuum glazing due to atmospheric pressure on the glass strength, the calculation formula of resistance to wind load for the vacuum glazing was given.

The conventional method of producing porcelain standard disc specimens is based on the dental lab method for bilayer ceramic crowns, in order to reflect the clinical using condition. However heavy task is facing to the researchers, which is producing a large amount of the specimens efficiently. The press molding method is used to produce dental porcelain disc specimens in this study. Then, the basic mechanical properties of two groups of porcelain specimens were tested respectively, comparing with handmade and press molding method. The density was measured by Archimedes' method, the flexural strength was tested by biaxial bending test, and the hardness was checked by microhardness tester. The micro features of the specimens before and after bending test were observed under optical microscope and SEM. The results showed that there was no significant difference in the flexural strength, microhardness and density of porcelain discs made by two methods. Air pores were found in all specimens with size between 5-50 micrometers. The size and distribution of pores in the specimens by press molding method are more homogeneous than handmade method. Producing dental porcelain discs for laboratory testing specimens by press molding method was much easy than handmade method. Furthermore, the mechanical properties and microstructures of the specimens made by handmade method and press molding method were almost same.

The residual strength of dental porcelain discs were test after cycling fatigue compressive load in this study. Moreover, the effects of stress intensity and cycle frequency to the damage of porcelain were explored. The porcelain specimens were bonded to the epoxy resin blocks, with 12.5mm height. The cycling fatigue contact loads were subjected on the porcelain surfaces of the bi-layer composites with silicon nitride spheres of radius 2.5mm. The crosshead speed was 6mm/min. The top load value was varied from 10N-20N in every load cycles. The cycling number was from 50-300. After cycling test, the residual strength of all porcelain samples was measured by bi-axial bending test. Fractured pieces of the specimens were collected and examined with optical microscope and SEM. On the fracture surfaces of porcelain discs after bi-axial bending test, Hertz cone cracks were presented due to cycling fatigue load. The result showed that the residual strength of dental porcelain had negative correlation with the fatigue load values and cycles. When the fatigue load cycles were lower than 100, the residual strength of porcelain presented no significant different under 10 or 20N fatigue load. In contrary, when the fatigue load cycles were over 100, the residual strength of porcelain was much lower under 20N fatigue load than 10N fatigue load. Based on the limited results of this study, the conclusion could be drawn that the residual strength of porcelain under fatigue compressive stress was main determined by load cycles in the range of small load values. The porcelain could be destroyed after very few cycles if the load is up to a critical value.

A novel new algorithm of path planning is proposed for the robot path planning based on the local data map in the robot autonomous navigation. The algorithm is used to search for the local optimal path from the current position of the robot to the target according to the known sensor data. If the robot cannot reach the target directly, the temporary target point which the robot can reach will be set up according to the optimal path. The algorithm is effective under the complicated unknown environment and moving obstacle situation which fast searching speed, it can be adapted into the practical applications and the multi-robot harmony easily. The simulation result shows that this method can provide a better planning path by comparing with the traditional planning algorithms such as artificial potential field and wall-following

Considering the large deformation of the hose pipe diameter caused by the pressure, this paper revises the hydraulic capacity on the basis of physical model of pipe-wall, establishes the mathematical model of the hose by lumped parameter model of pipe, builds the model of the system composed of the constant pressure oil source and flow valve using Simulink software and simulates the hydraulic impact by changing the pipe diameter and length. The established hose model and simulation results can provide reference for the related research.

Adhesion is one of the most important mechanical properties of ceramic coatings. Scratch testing is considered as a simple and effective method to evaluate adhesion of ceramic coatings. In this paper, the critical normal forces and scratch morphologies for different coating-substrate systems were studied by scratch testing. It is shown that the critical normal force obtained by acoustic emission (AE) signals decreases from 12 N to 7 N when the applied normal force rate increases from 20 N/min to 100 N/min for CVD SiC on C, and the failure area of this scratched sample increases with increasing maximum normal force; Based on scratch morphologies, spallation or delamination can be observed for hard-brittle coatings on glass or metal, while discontinuous or continuous ductile perforation can be observed for ductile coatings on metal; The critical normal force for hard-brittle coatings can be effectively obtained by AE signals.

The portal frame is one kind of the common structural styles in the light steel structure. And the portal frame is designed by tapered members, which can be suitable for the variety of the bending moment diagram. This paper introduces the new structure dividing the middle column into two parts on the top of the middle column and analysis the frame with SAP2000. The parameters are investigated such as the hinge joint and firm joint at the bottom of the column and also the parameter of the science of geometry, which influence the load-carrying behavior of the portal frame. The analysis gives that it’s avail for the frame if the angle of the dividing is thirty. Besides, some corresponding design proposal is obtained according to the analysis of the internal force.

Aluminium alloy members under axial force have broad application in structural field. Owing to low elastic modulus, aluminium alloy members are easier buckling than steel members. Based on the reasonable and equivalent calculation model and the related calculation formulas of rotational restraint stiffness kφ, lateral restraint stiffness kx, and distortional buckling critical half-wave length λ that provided by lipped channel web plate to flange under longitudinal distribution stress, the distortional buckling load calculation formula of the lipped channel is derived combining the thin-walled bar buckling theory in elastic medium. The distortional buckling loads and distortional buckling critical half-wave lengths at the different wall thickness have been calculated using the calculation formulas of this paper, and the results have been comparatived with the finite strip method. The comparison results show that: the average ratio of caculation results from formulas of this paper and results from CUFSM is 0.997and0.971 respectively,the corresponding variance is 2.9*10-5and 7.5*10-5. So the calculation results of this paper is in good agreement with the finite strip software, the calculation formula of this paper has enough calculation precision and good stability. At the same time, the calculation results of this paper is more concise than calculation formula for the same type, easy to be applied, may be used in practical applications and taken account into design codes and guidelines.