Vacuum ultrasonic vibrating fatigue experimental system
Technical field
The present invention relates to fatigue rig technical field, the fatigue property test of material when for vacuum environment, particularly relate to a kind of vacuum ultrasonic vibrating fatigue experimental system.
Background technology
The important plant equipment relevant to vacuum environment condition, such as steam turbine low-pressure aspirating air pipe, various seating planes, military aircraft are in the high cruise stage, spacecraft and satellite etc., its working environment is compared with normal atmospheric pressure, air pressure declines a lot, all for being operated in different vacuum environment.In apparatus above military service process, these parts can be subject to Very High Cycle cycle (as > 107Cycle, determine according to design life) repeat load effect, apparatus above mostly is Grand Equipments, for ensureing its safety and reliability in life cycle, it is necessary to the super high cycle fatigue behavior under different vacuum environmental conditions of the analysis and research metal material.
Existing supersonic vibration fatigue experiment system can realize the fatigue loading of normal atmospheric conditions, hot environment, corrosive environment.Existing supersonic vibration fatigue test system can not carry out fatigue loading simulation when vacuum environment, for the equipment component worked in above in different vacuum environment, testing fatigue condition is different from the actual working environment of corresponding parts, and this allows for existing supersonic vibration fatigue test system can not accurately, objectively simulate the anti-periodic vibration fatigue behaviour of above parts.
Summary of the invention
Fatigue loading simulation when vacuum environment can not be carried out for above-mentioned existing supersonic vibration fatigue test system, for the equipment component worked in above in different vacuum environment, testing fatigue condition is different from the actual working environment of corresponding parts, this allows for the problem that existing supersonic vibration fatigue test system can not accurately, objectively simulate the anti-periodic vibration fatigue behaviour of above parts, the invention provides a kind of vacuum ultrasonic vibrating fatigue experimental system.
For the problems referred to above, vacuum ultrasonic vibrating fatigue experimental system provided by the invention is achieved the goal by techniques below main points: vacuum ultrasonic vibrating fatigue experimental system, including piezoelectric transducer and supersonic signal generator, the electrical energy inputs of described piezoelectric transducer is connected on the ac signal outfan of supersonic signal generator, also include vacuum tank, the test specimen being connected on described piezoelectric transducer mechanical vibration outfan is arranged in described vacuum tank, described vacuum tank is connected to negative pressure also by vacuum tube and produces equipment.
Concrete, the vacuum tank of arrangement above, for providing low-voltage vacuum periodic vibration fatigue experiment environment for test specimen, the supersonic signal generator arranged is for converting the high-frequency ac signal of telecommunication to civil power or other power sources, piezoelectric transducer is for converting the described high-frequency ac signal of telecommunication to mechanical oscillation signal, so, above mechanical oscillation signal acts on test specimen, can make test specimen execution cycle vibrating fatigue experiment in a certain low pressure vacuum environment.So, this device, compared to existing vibrating fatigue experimental facilities, can simulate the practical vacuum environment of tested test specimen, it is simple to obtains directly reflecting that test specimen is under low pressure vacuum environment, the numerical value of periodic vibration experiment on fatigue properties accurately or measure numerical value.
Further technical scheme is:
Owing to no matter existing piezoelectric transducer adopting monocrystalline or ceramic material, the mechanically deform displacement obtained is all only small, as only having several microns, for amplifying with top offset, to obtain measured value more accurately, being also associated with displacement amplifier on the mechanical vibration outfan of described piezoelectric transducer, the fixing end of the test specimen of described displacement amplifier is positioned at described vacuum tank.It is different that described displacement amplifier is based on different parts displacement during resonance, it is achieved the amplification of vibration displacement.The more commonly used shape has: index shape, cone, stairstepping displacement amplifier.
Testing for ease of changing different test specimens, described vacuum tank includes upper box and lower box, and described upper box and lower box are in removably connecting relation, and are additionally provided with sealing ring on the joint face of upper box and lower box.More than the relation of removably connecting can be with bolts etc. form realized.
For ease of needing to be formed in vacuum tank rapidly rough vacuum environment and condition of high vacuum degree environment according to experiment, described negative pressure produces equipment and includes the first vacuum pump and the second vacuum pump, described first vacuum pump and the second vacuum pump are connected with the inner chamber of vacuum tank each through vacuum tube, and vacuum tube is additionally provided with the first electromagnetic valve and the second electromagnetic valve, described first electromagnetic valve and the second electromagnetic valve can be respectively used to realize the second vacuum pump and the first vacuum pump individually connects with vacuum tank inner chamber respectively, and the vacuum pump ultimate pressure of described second vacuum pump and the first vacuum pump is not etc..Above rough vacuum environment is relative with condition of high vacuum degree environment, described vacuum pump ultimate pressure refers to the maximum vacuum that this vacuum pump can extract, this programme is set to negative pressure generation equipment and includes the first vacuum pump and the second vacuum pump, facilitate implementation: if the vacuum required for experiment is relatively low, by opening the first vacuum pump and the relatively low vacuum pump of the second vacuum pump intermediate pump ultimate pressure, rapidly be required vacuum;When the vacuum that experiment is required is higher, by opening the first vacuum pump and the relatively low vacuum pump of the second vacuum pump intermediate pump ultimate pressure, after obtaining the maximum vacuum that this pump can reach, open another vacuum pump, obtain the required vacuum that vacuum is higher.It is preferably arranged to above first vacuum pump and the second vacuum pump respectively rotary-vane vaccum pump and water-ring vacuum pump, with vacuum in vacuum tank not high time, by the rapid Raise vacuum degree of water-ring vacuum pump, when needs improve vacuum further, open rotary-vane vaccum pump.
For ease of realizing native system periodic vibration and loading and control, the automatically controlling of vacuum size, also include controller, described supersonic signal generator control end and/or outfan is electrically connected with the controller, described negative pressure produces the control end of equipment and/or feedback end is electrically connected with the controller.
For ease of obtaining the temperature value of the size of vacuum and the lower test specimen of experiment in vacuum tank intuitively, realize the linkage of vacuum and periodic vibration fatigue loading in test specimen temperature, vacuum tank, also include the temperature measurer and the vacuum test instrument that are electrically connected with the controller, the end of measuring of described vacuum test instrument is positioned at the intracavity of vacuum tank, and described temperature measurer is for measuring the temperature of test specimen.
As a kind of temperature measurer implementation be easy to and be arranged at outside vacuum tank, described temperature measurer is infrared temperature measurement apparatus.
For ease of realizing test specimen in vacuum tank being observed, measuring the purposes such as test specimen temperature by the temperature measurer being arranged at outside vacuum tank, described vacuum tank is additionally provided with glass transparent form.Further, for the benefit of native system life-span or reduce fault rate, described glass transparent form adopt high intensity, low-expansion glass.
As a kind of specific implementation being easy to improve native system conventional efficient, described supersonic signal generator is the ultrasonic signal generating device that exportable frequency is not less than the ultrasonic sine wave signal of 20kHz.By this programme, if loading frequency is 20kHz, it is possible to be conveniently carried out rapid ultra high week fatigue experiment, 1 × 10 can be realized within one day9The CYCLIC LOADING of cycle, and adopt the high-cycle fatigue experimental machine of traditional 50Hz, take around the time of 230 days, greatly shorten experimental period so that in process of scientific research, carry out 109Above super high cycle fatigue research has higher feasibility.Therefore this programme can realize: reach superelevation cycle fatigue loading at short notice, relative to classic fatigue testing machine, it is possible to save the plenty of time, the energy resource consumption of equipment is greatly decreased.
Also including the displacement transducer for detecting test specimen vibration displacement, above displacement transducer is mainly used in before experiment starts, the amplitude of calibration experiment system, to ensure that system stability runs reliably.
The method have the advantages that
In the present invention, the vacuum tank of arrangement above, for providing low-voltage vacuum periodic vibration fatigue experiment environment for test specimen, the supersonic signal generator arranged is for converting the high-frequency ac signal of telecommunication to civil power or other power sources, piezoelectric transducer is for converting the described high-frequency ac signal of telecommunication to mechanical oscillation signal, so, above mechanical oscillation signal acts on test specimen, can make test specimen execution cycle vibrating fatigue experiment in a certain low pressure vacuum environment.So, this device, compared to existing vibrating fatigue experimental facilities, can simulate the practical vacuum environment of tested test specimen, it is simple to obtains directly reflecting that test specimen is under low pressure vacuum environment, the numerical value of periodic vibration experiment on fatigue properties accurately or measure numerical value.
Simultaneously, adopt piezoelectric transducer and supersonic signal generator as mechanical vibration generating element, it is easy to obtain that workpiece carries out quickly even high-cycle fatigue load, reach Very High Cycle cycle fatigue loading at short notice, relative to classic fatigue testing machine, the plenty of time can be saved, the energy resource consumption of equipment is greatly decreased, such as the supersonic signal generator of ultrasonic sine wave signal adopting output frequency to be 20kHz and the piezoelectric transducer mated with this ultrasonic sine wave signal.
Accompanying drawing explanation
Fig. 1 is the structural representation of vacuum ultrasonic one specific embodiment of vibrating fatigue experimental system of the present invention.
Label in figure represents respectively: 1, upper box, and 2, lower box, the 3, second vacuum pump, 4, the first vacuum pump, 5, vacuum tube, the 6, first electromagnetic valve, 7, the second electromagnetic valve, 8, vacuum test instrument, 9, controller, 10, supersonic signal generator, 11, piezoelectric transducer, 12, displacement amplifier, 13, test specimen, 14, temperature measurer, 15, glass transparent form.
Detailed description of the invention
Below in conjunction with embodiment, the present invention is described in further detail, but the structure of the present invention is not limited only to following example.
Embodiment 1:
As shown in Figure 1, vacuum ultrasonic vibrating fatigue experimental system, including piezoelectric transducer 11 and supersonic signal generator 10, the electrical energy inputs of described piezoelectric transducer 11 is connected on the ac signal outfan of supersonic signal generator 10, also include vacuum tank, the test specimen 13 being connected on described piezoelectric transducer 11 mechanical vibration outfan is arranged in described vacuum tank, described vacuum tank is connected to negative pressure also by vacuum tube 5 and produces equipment.
Concrete, the vacuum tank of arrangement above, for providing low-voltage vacuum periodic vibration fatigue experiment environment for test specimen 13, the supersonic signal generator 10 arranged is for converting the high-frequency ac signal of telecommunication to civil power or other power sources, piezoelectric transducer 11 is for converting the described high-frequency ac signal of telecommunication to mechanical oscillation signal, so, above mechanical oscillation signal acts on test specimen 13, can make test specimen 13 execution cycle vibrating fatigue experiment in a certain low pressure vacuum environment.So, this device, compared to existing vibrating fatigue experimental facilities, can simulate the practical vacuum environment of tested test specimen 13, it is simple to obtains directly reflecting that test specimen 13 is under low pressure vacuum environment, the numerical value of periodic vibration experiment on fatigue properties accurately or measure numerical value.
Embodiment 2:
As shown in Figure 1, the present embodiment is further qualified on the basis of embodiment 1: owing to no matter adopting monocrystalline or ceramic material in existing piezoelectric transducer 11, the mechanically deform displacement obtained is all only small, as only having several microns, for amplifying with top offset, to obtain measured value more accurately, the mechanical vibration outfan of described piezoelectric transducer 11 being also associated with displacement amplifier 12, the fixing end of the test specimen of described displacement amplifier 12 is positioned at described vacuum tank.It is different that described displacement amplifier 12 is based on different parts displacement during resonance, it is achieved the amplification of vibration displacement.The more commonly used shape has: index shape, cone, stairstepping displacement amplifier 12.In the present embodiment, displacement amplifier 12 adopts the shape that circular cone combines with stairstepping, conical section will be located in amplifier stretches into for connecting test specimen 13 in vacuum tank, and the outside wall surface laminating of stairstepping place and vacuum tank is used for ensureing that in vacuum tank, space seals off relative to the external world.
Testing for ease of changing different test specimens 13, described vacuum tank includes upper box 1 and lower box 2, and described upper box 1 and lower box 2 are in removably connecting relation, and are additionally provided with sealing ring on the joint face of upper box 1 and lower box 2.More than the relation of removably connecting can be with bolts etc. form realized.
For ease of needing to be formed in vacuum tank rapidly rough vacuum environment and condition of high vacuum degree environment according to experiment, described negative pressure produces equipment and includes the first vacuum pump 4 and the second vacuum pump 3, described first vacuum pump 4 and the second vacuum pump 3 are connected with the inner chamber of vacuum tank each through vacuum tube 5, and vacuum tube 5 is additionally provided with the first electromagnetic valve 6 and the second electromagnetic valve 7, described first electromagnetic valve 6 and the second electromagnetic valve 7 can be respectively used to realize the second vacuum pump 3 and individually connect with vacuum tank inner chamber respectively with the first vacuum pump 4, the vacuum pump ultimate pressure of both described second vacuum pump 3 and the first vacuum pump 4 is not etc..Above rough vacuum environment is relative with condition of high vacuum degree environment, described vacuum pump ultimate pressure refers to the maximum vacuum that this vacuum pump can extract, this programme is set to negative pressure generation equipment and includes the first vacuum pump 4 and the second vacuum pump 3, facilitate implementation: if the vacuum required for experiment is relatively low, by opening the first vacuum pump 4 and the relatively low vacuum pump of the second vacuum pump 3 intermediate pump ultimate pressure, rapidly be required vacuum;When the vacuum that experiment is required is higher, by opening the first vacuum pump 4 and the relatively low vacuum pump of the second vacuum pump 3 intermediate pump ultimate pressure, after obtaining the maximum vacuum that this pump can reach, open another vacuum pump, obtain the required vacuum that vacuum is higher.It is preferably arranged to above first vacuum pump 4 and the second vacuum pump 3 respectively rotary-vane vaccum pump and water-ring vacuum pump, with vacuum in vacuum tank not high time, by the rapid Raise vacuum degree of water-ring vacuum pump, when needs improve vacuum further, open rotary-vane vaccum pump.In the present embodiment, described vacuum tube 5 includes a three way cock and is connected to three fairleads on three way cock's difference adapter end, the other end of three fairleads is connected with the suction side of the first vacuum pump 4, the suction side of the second vacuum pump 3 and the inner chamber of vacuum tank respectively, and the first electromagnetic valve 6 or the second electromagnetic valve 7 are series on the fairlead between three way cock and the first vacuum pump 4 or the second vacuum pump.
In the present embodiment, the control end of described first electromagnetic valve the 6, second electromagnetic valve 7 all electrically connects with controller 9, in order to by controller 9, the on off state of the first electromagnetic valve 6 and the second electromagnetic valve 7 is automatically controlled.
For ease of realizing native system periodic vibration and loading and control, the automatically controlling of vacuum size, also include controller 9, described supersonic signal generator 10 control end and/or outfan electrically connects with controller 9, the described negative pressure generation control end of equipment and/or feedback end electrically connect with controller 9.
For ease of obtaining the temperature value of the size of vacuum and the lower test specimen 13 of experiment in vacuum tank intuitively, realize the linkage of vacuum and periodic vibration fatigue loading in test specimen 13 temperature, vacuum tank, also include the temperature measurer 14 and the vacuum test instrument 8 that electrically connect with controller 9, the end of measuring of described vacuum test instrument 8 is positioned at the intracavity of vacuum tank, and described temperature measurer 14 is for measuring the temperature of test specimen 13.
As a kind of temperature measurer 14 implementation be easy to and be arranged at outside vacuum tank, described temperature measurer 14 is infrared temperature measurement apparatus.
For ease of realizing test specimen in vacuum tank 13 being observed, measuring the purposes such as test specimen 13 temperature by the temperature measurer 14 being arranged at outside vacuum tank, described vacuum tank is additionally provided with glass transparent form 15.Further, for the benefit of native system life-span or reduce fault rate, described glass transparent form 15 adopts high intensity, low-expansion glass.
Embodiment 3:
As shown in Figure 1, the basis of any one technical scheme that the present embodiment provides in above example is further qualified: as a kind of specific implementation being easy to improve native system conventional efficient, described supersonic signal generator 10 is the ultrasonic signal generating device that exportable frequency is not less than the ultrasonic sine wave signal of 20kHz.By this programme, if loading frequency is 20kHz, it is possible to be conveniently carried out rapid ultra high week fatigue experiment, 1 × 10 can be realized within one day9The CYCLIC LOADING of cycle, and adopt the high-cycle fatigue experimental machine of traditional 50Hz, take around the time of 230 days, greatly shorten experimental period so that in process of scientific research, carry out 109Above super high cycle fatigue research has higher feasibility.Therefore this programme can realize: reach superelevation cycle fatigue loading at short notice, relative to classic fatigue testing machine, it is possible to save the plenty of time, the energy resource consumption of equipment is greatly decreased.
Also including the displacement transducer for detecting test specimen 13 vibration displacement, above displacement transducer is mainly used in before experiment starts, the amplitude of calibration experiment system, to ensure that system stability runs reliably.
Above content is the further description present invention made in conjunction with concrete preferred implementation, it is impossible to assert that the specific embodiment of the present invention is confined to these explanations.For general technical staff of the technical field of the invention, without departing from other embodiments drawn under technical scheme, should be included in protection scope of the present invention.