Utility model content
The utility model is made based on the above-described state of the art, its objective is and provides a kind of flexible joint for aircraft fuel oil pipeline to carry out the system of limit shear test.By this system, can obtain the flexible joint that will select in airplane design in limit shear-type load situation, its stress and distortion (or extend) situation, and the relation between stress and deflection and the loading force of flexible joint can be provided.
Above-mentioned purpose of the present utility model realizes by a kind of limit shear test system for the flexible joint of aircraft fuel oil pipeline, this limit shear test system comprises: flexible joint assembly to be measured, flexible joint assembly comprises the first conduit, the second conduit and is connected to the flexible joint between them, the first conduit comprises the first outer tube and the first inner tube, the second conduit comprises the second outer tube and the second inner tube, wherein in the first inner tube and the second inner tube, be filled with pressure fluid, the first conduit is fixed on test platform by stationary fixture; Drawing machine, drawing machine has mobile terminal and stiff end, and the mobile terminal of drawing machine is connected with the second conduit by movable clamp, and can be along moving with the perpendicular direction of the axis of flexible joint assembly, and the stiff end of drawing machine is fixed on test platform; Tensimeter, tensimeter is arranged on flexible joint assembly, for measuring the hydrodynamic pressure of the first inner tube and the second inner tube; Displacement transducer, displacement transducer is arranged on the second conduit; Pull pressure sensor, pull pressure sensor is arranged on the mobile terminal place of drawing machine; And at least one foil gauge, foil gauge is attached in flexible joint.
By limit shear test system of the present utility model, can test the shear-type load situation of the flexible joint of aircraft fuel oil pipeline, thereby fully examine the limit shearing design of the flexible joint of aircraft fuel oil pipeline whether to meet the demands.Specifically, limit shear test system of the present utility model can be measured flexible joint its stress state and deformation in the situation that having loaded shearing force, and can draw according to obtained data the corresponding relation curve of shearing force and stress/distortion, and, can detect the yield shear stress of flexible joint under certain working pressure.
Further, this limit shear test system also comprises pressurizing device, and pressurizing device is communicated with the first inner tube and/or the second interior pipe fluid.This pressurizing device carries out pressurising to the first inner tube and the second inner tube, so that flexible joint component internal reaches needed maximum pressure.
Preferably, one end of the first conduit is connected with flexible joint, is provided with the first plug on the other end of the first conduit; One end of the second conduit is connected with flexible joint, is provided with the second plug on the other end of the second conduit.By plug is set, realize the pressure of flexible joint component internal is kept.
Preferably, between the first outer tube and the first inner tube and between the second outer tube and the second inner tube, be filled with normal pressure fluid.This normal pressure fluid can be the liquid that has added coloring agent, thereby contributes to operating personnel to observe the seepage situation of flexible joint assembly.
In addition, pressure fluid also can be liquid.
Preferably, foil gauge being circumferentially evenly arranged along flexible joint.
In one embodiment, flatly stretch out mounting frame for sensor from movable clamp, one end of displacement transducer is connected in mounting frame for sensor, and the other end of displacement transducer is fixed on test platform.
In the accessible strainmeter of foil gauge and/or displacement transducer.By strainmeter, foil gauge and the detected signal of displacement transducer are carried out to corresponding calculating and infusion processing, thereby can determine better the stress level of flexible joint assembly under the effect of shear-type load.
Embodiment
Below in conjunction with Fig. 1-4, specific embodiment of the utility model is described.It should be noted that, shown in accompanying drawing is only preferred embodiment of the present utility model, and it does not form the restriction to protection domain of the present utility model.Technician in association area can make various equivalent transformations to details wherein, and these equivalent transformations are equally within the desired protection domain of the utility model.
Fig. 1 shows the stereographic map of the limit shear test system 1 of aircraft fuel oil pipeline of the present utility model flexible joint.As can be seen from Fig. 1, limit shear test system 1 comprises flexible joint assembly to be measured.This flexible joint assembly comprises flexible joint 10, is connected with respectively the first conduit 11a and the second conduit 11b at the two ends of flexible joint.The first conduit 11a is fixed on test platform 42 by the stationary fixture 43 of drawing machine, and the stiff end (not shown) of drawing machine is fixed on this test platform, and the second conduit 11b is connected with the mobile terminal 41 of drawing machine by movable clamp 44.The measurement mechanisms such as tensimeter 21, displacement transducer 22, pull pressure sensor 23, foil gauge 24 are also installed on flexible joint assembly.
Below, will the various piece of limit shear test system 1 of the present utility model be described.
The flexible joint assembly > that < is to be measured
Fig. 2 shows the schematic diagram of flexible joint assembly to be measured in limit shear test system 1 of the present utility model.
As shown in Figure 2, flexible joint assembly comprise the first conduit 11a, the second conduit 11b and be connected to the first conduit and the second conduit between flexible joint 10.The first conduit 11a comprises the first outer tube 12a and the first inner tube 13a, thereby forms double-layer tube structure.One end of the first conduit 11a is connected with flexible joint 10.On the other end of the first conduit 11a, be provided with the first plug 14a.
In the same manner, the second conduit 11b is also the double-layer tube structure that comprises the second outer tube 12b and the second inner tube 13b, and its one end is connected with flexible joint 10, is provided with the second plug 14b on the other end.
Preferably, the first conduit 11a tucks inside the sleeve by pipe and is connected with flexible joint 10 with the second conduit 11b.Specifically, the first conduit 11a is connected with the outer tube joint of flexible joint 10 by pipe sleeve 15a, the 15b shown in Fig. 2 with the second conduit 11b outer tube 12a, 12b separately; This two conduit 11a, 11b inner tube 13a, 13b separately is connected on the inner pipe joint of flexible joint 10 by each self-corresponding pipe sleeve (not shown).
In inner tube 13a, 13b, inflatable has the liquid such as water, and as required the liquid in inner tube is remained under certain pressure.For example, the fluid pressure in inner tube can be remained on to 60psi left and right.For example, in flexible joint assembly, be provided with tensimeter 21 in the first conduit 11a, be used for measuring the pressure in flexible joint assembly.Between outer tube separately of the first conduit and the second conduit and inner tube, be filled with liquid.Liquid between outer tube and inner tube can be normal pressure, and can be added with for example red coloring agent.
The preparation process of flexible joint assembly is as follows:
First, according to test needs, choose the pipeline of certain length, to be used as the first conduit 11a and the second conduit 11b.For example, intercept out the pipeline of Len req from one section of longer pipeline.Preferably, selected the first conduit 11a and the second conduit 11b can have following length, make the conduit about 180mm that stretches out from its commissure.Preferably, the fracture of intercepted pipeline is cleaned and polished.
Then, the first plug 14a is connected on one end of the first conduit 11a.Connection between the first plug 14a and the first conduit 11a can realize by cementing agent, for example, can adopt the AB glue that shear resistance is higher.At the other end place of the first conduit 11a, the device of tucking inside the sleeve and so on by pipe is connected the first inner tube 13a with the inner pipe joint in flexible joint 10.
In an identical manner, the second plug 14b is installed in one end of the second conduit 11b, and at the other end place of the second conduit 11b, its inner tube 13b is connected on the inner pipe joint of flexible joint 10.
The first plug 14a and the second plug 14b contribute to the liquid in the first inner tube 13a and the second inner tube 13b to remain under certain pressure.
Then, flexible joint assembly is immersed among the liquid such as water, and in the atmosphere of this liquid, the first conduit 11a and the second conduit 11b outer tube 12a, 12b are separately connected on the outer tube joint of flexible joint 10.
Thus, in mounted flexible joint assembly, between the first outer tube 12a of the first conduit 11a and the first inner tube 13a and be filled with the liquid of normal pressure between the second outer tube 12b of the second conduit 11b and the second inner tube 13b, for example water, this liquid is preferably added with coloring agent.
< experimental measurement device >
The setting of the experimental measurement device in limit shear test system 1 of the present utility model is described in connection with Fig. 3 below.
Tensimeter 21 is set in flexible joint assembly, to be used for monitoring the fluid pressure in flexible joint assembly.For example, in the situation shown in Fig. 3, tensimeter 21 is connected in the first inner tube 13a of the first conduit 11a.Preferably, need to carry out Real-Time Monitoring to flexible joint component internal pressure, therefore tensimeter 21 can comprise digital manometer and supporting pressure transducer.Gather in real time the hydraulic data of flexible joint component internal by pressure transducer.The range of tensimeter 21 can be 0 to 2MP, and its measuring accuracy is 1%.
By the Real-Time Monitoring to catheter interior pressure, can judge whether flexible joint assembly lost efficacy under the effect of load, thereby can draw the limit shear-type load of flexible joint.
On the second conduit 11b, connect or be fixed with the mobile terminal 41 of drawing machine.For example, as shown in figs. 1 and 3, movable clamp 44 is arranged on the connecting portion between the second conduit 11b and flexible joint 10.The stiff end of drawing machine is fixed on test platform 42, and is connected with the first conduit 11a by stationary fixture 43.
At this, the drawing machine adopting can be that model is the universal electrical testing machine of WDW-E200D, and its range is 200KN, and demarcating rank is 1 grade.The load range of considering this testing machine is larger, and therefore the degree of accuracy of its measurement thereby also lower, for guaranteeing measuring accuracy, preferably can install a pull pressure sensor 23 additional at the point of application place of drawing machine.For example, the LTR load transducer of a small-range can be installed, its measuring error is 1%.
The position that approaches load applying position at the second conduit 11b is provided with displacement transducer 22, is used for measuring the tangential displacement of the second conduit 11b under shearing force effect.As shown in Figure 1, movable clamp 44 approximate horizontal ground extend mounting frame for sensor 32, and one end of displacement transducer 22 is fixed on mounting frame for sensor 32, and the other end is fixed on test platform.
It is the displacement transducer of THD-20 and THD-50 that this displacement transducer 22 can adopt model.The error range of this displacement transducer is 1%, and measuring accuracy is 0.01mm.
In flexible joint 10 along circumferentially distributing equably some measurement points, to measure the deformation of flexible joint assembly under load.
According to measuring needs, on flexible joint assembly, choose some positions, paste foil gauge 24 on these positions, foil gauge 24 is connected with strainmeter, thereby by the measurement of strain and corresponding calculating and data processing, monitor the strain level of flexible joint assembly under shear-type load.For example, in flexible joint 10, circumferentially paste equably several foil gauges 24 along it, for example, paste two foil gauges 24.Herein, foil gauge 24 can be resistance strain plate, and it is the statical strain indicator of DH3818 that strainmeter can be selected model, and its error range is 3%.
< limit shear-type load test >
The process of the limit shear-type load test of being undertaken by limit shear test system of the present utility model will be illustrated below.
First, assemble limit shear test system of the present utility model, comprising following installation steps.It should be noted that, following narrative order does not represent actual erection sequence.In practical operation, can adjust as required the erection sequence of limit shear test system.
The flexible joint assembly to be measured assembling is connected in pressurizing device, so that flexible joint assembly is carried out to pressurising, for example, fills fluid under pressure.Specifically, be that the first inner tube 13a and the second inner tube 13b are carried out to pressurising.Preferably, in Plenum Process, the initial gap between the pipe sleeve end face of the first inner tube 13a and the second inner tube 13b is 3.175mm.
An example that flexible joint assembly is carried out to the pressurizing device 50 of pressurising has been shown in Fig. 4.Wherein, for example, at a side (the first conduit 11a mono-side) Bonding pressure table 21 and the stop valve 53 of flexible joint assembly, and be connected to liquid storage tank 52, and for example, at the opposite side (the second conduit 11b mono-side) of flexible joint assembly pump 51 being installed, this pump 51 is also connected with liquid storage tank 52.Between pump 51 and liquid storage tank 52, filtrator 54 can be set.
Pressurizing device is above exemplary, also can adopt other known pressurizing device to carry out pressurising to flexible joint assembly.
Pressurising step is as follows:
I. the flexible joint assembly assembling is connected in the pressure application system shown in Fig. 4, and is placed into as illustrated in fig. 2 on pressurising support 33.
Ii. according to 10% pressurization step by step of the maximum pressure in inner tube.For example, in the situation that is 60psi at maximum pressure, the 6psi that at every turn pressurizes, until the pressure in inner tube reaches maximum pressure 60psi.
Flexible joint assembly good pressurising is installed on test platform, and is connected with drawing machine.For example, as shown in Figure 1, the first conduit 11a is fixed on test platform 42 by stationary fixture 43, and the second conduit 11b is connected with the mobile terminal 41 of drawing machine by movable clamp 44.In this process, the pressure in inner tube 13a, 13b in flexible joint assembly should keep stable, maintains maximum pressure place.
Be noted that at this flexible joint assembly should be mentioned that good pressurising is installed on test platform herein.But, also can first flexible joint assembly be installed on test platform, then on test platform, flexible joint assembly is carried out to pressurising.
Various sensors and measurement mechanism are installed on flexible joint assembly, comprising:
Foil gauge 24 is set in flexible joint 10, for example, respectively pastes up and down a slice foil gauge at the center position of flexible joint 10, thereby two foil gauges 24 are set altogether.Foil gauge 24 is accessed to strainmeter.
Installation position displacement sensor 22 on the second conduit 11b.For example, one end of displacement transducer 22 is fixed on from the movable clamp 44 extended mounting frame for sensor 32 in approximate horizontal ground, and the other end is fixed on test platform 42.Displacement transducer 22 is accessed to strainmeter.
After assembling limit shear test system, by drawing machine, flexible joint assembly is applied to shearing force lentamente.Specifically, the mobile terminal of drawing machine is along moving with the perpendicular direction of the axis of flexible joint assembly.In the process that applies shearing force, by the fluid pressure in pressure sensor monitoring inner tube 13a, 13b in tensimeter 21, to judge whether flexible joint assembly lost efficacy under the effect of shearing force.Meanwhile, leakage situation that can manual observation outer tube, to assist the judgement to flexible joint component failures.
In the process loading, the loading speed of load is not more than 1mm/min.
Increase step by step applied shearing force according to the standard of every grade of 0.1KN.In the load on process of every one-level, measure the hydraulic pressure value of flexible joint component internal, measure strain level that flexible joint 10 bears and measure the deflection of flexible joint 10 by displacement transducer 22 with along the measurement point of the circumferential arrangement of flexible joint by foil gauge 24 by tensimeter 21.Record above-mentioned shearing force, hydraulic pressure value, strain level and deflection, and draw thus the corresponding relation of shearing force and hydraulic pressure value, strain level and deflection.
For example, can draw shearing force-hydraulic pressure value curve according to above-mentioned data, shear at least one in force-strain curve and shearing force-deflection curve.