216 results about "Structural temperature" patented technology

The invention provides a fatigue life prediction method for a high-modulus asphalt mixture pavement. The method comprises the steps that structural temperature distribution, pavement material dynamic modulus and temperature axle load distribution of the high-modulus asphalt mixture pavement serve as basis parameters; a fatigue strain equation is fit according to an indirect tension fatigue test result; ANSYS software is adopted to construct a pavement structure finite element model, and maximum tension strain of a bottom layer at different axle load levels in different temperature regions is calculated; according to the Miner fatigue cumulative damage rule, fatigue cumulative damage results of a high-modulus asphalt mixture at different axle loads and different temperatures are calculated according to the formula: . The fatigue life prediction method for the high-modulus asphalt mixture pavement has the technical advantages that temperature gradients and axle load distribution of the asphalt mixture pavement are fully considered, an accurate prediction model is established, the process and law of fatigue attenuation of the asphalt mixture are accurately described, the application range is wide, and calculation results are reliable, so a more reliable method is provided for structural design of the asphalt pavement.

The invention discloses a permanent magnet synchronous motor temperature rise heat dissipation analysis method based on the multi-field coupling technology. The method comprises the first step of carrying out the analysis of electromagnetic loss by the establishment of an electromagnetic field model of an electric machine to obtain the copper loss on a coil, the iron loss of an iron core and the eddy-current loss of permanent magnet materials, the second step of establishing a fluid solid strong coupling conjugate heat conduction model of the structural temperature field analysis and the fluid heat dissipation analysis of the electric machine, the third step of establishing a bothway weak coupling model of the electromagnetic loss and the fluid solid strong coupling conjugate heat conduction analysis, and the fourth step of achieving the convergence of a single physical model and the convergence of the load transferring between the electromagnetic field model and the fluid solid strong coupling conjugate heat conduction model by the adaptation of a repetitive cycle iterative method, wherein if the condition of the convergence meets the condition set by a user, the coupling is balanced, and the computing process is finished. The permanent magnet synchronous motor temperature rise heat dissipation analysis method integrates the advantages of the strong coupling and the weak coupling, the temperature rise and the heat dissipation process when the electric machine works are precisely simulated in a unified software platform, the stability of the convergence in the process of computing is enhanced, and computing precision and computing efficiency are improved.

This invention relates to temperature modifying method in an electric migration test of a silicon chip level metal test structure, which modifies temperature of an actual test result so as to get an accurate metal electric migration life time value including: applying a fixed acceleration current to rise the temperature of the metal test structure relying on the heat generated by current, getting a set of test data T1-Tn and related invalid time t1-tn by measuring temperatures of multiple metal test structures, applying a data normalization way to take common temperature value T' of a set of the temperature values T1-Tn of the actual test structure as the parameter of a conversion formular to further get the invalid time t1'-tn' of the corresponding metal test structure so as to reflect the electric migration acceleration process corresponding to specific current in deed so as to extrapolate its life time quickly and accurately.

The invention discloses a coupling computing method of dynamic elasticity characteristics of a high supersonic velocity flight vehicle. Starting from physical field characteristic times like aerodynamic force, aerodynamic heat, structural heat transfer and structural stress/deformation, on the premise of considering existing computing resources and not lowering coupling computing precision, the computing amount of a coupling analysis method is effectively reduced, and the coupling computing method can be applied to hot-gas dynamic elasticity analysis of an actual structure of the high supersonic velocity flight vehicle. By monitoring the change condition of the structural temperature field, dynamic adjustment of the coupling time step length can be achieved, and on the condition of effectively guaranteeing the coupling computing precision, the problem of improving the coupling computing efficiency by a large margin is solved. According to the coupling computing method of the dynamic elasticity characteristics of the high supersonic velocity flight vehicle, hot-gas dynamic elasticity characteristic analysis of whole-machine structure or parts of the high supersonic velocity flight vehicle can be effectively achieved; meanwhile, for flow-heat-solid coupling computing problems like the aerodynamic heat and heat transfer coupling problem and the structural heat safety evaluation problem which are also related to the flight vehicle, the coupling computing method also has the solving capability.

The invention discloses a porous temperature-sensitive gel coated slow-release fertilizer prepared by a freeze polymerization method and a preparation method thereof. The preparation method comprisesthe following steps: sodium alginate is subjected to oxidization treatment by using sodium periodate as an oxidant, so as to obtain oxidized sodium alginate, and urea is coated by using the oxidized sodium alginate as a base material, so as to obtain sodium alginate-coated urea microspheres; and a polymer poly(N-isopropylacrylamide) gel is synthesized by the freeze polymerization method, so as toobtain a porous structural temperature-sensitive gel, and the slow-release fertilizer is obtained through fluidized bed spray granulation by using the porous structural temperature-sensitive gel as acoated material. According to the porous temperature-sensitive gel coated slow-release fertilizer prepared by the freeze polymerization method and the preparation method thereof, in the synthesis of the poly(N-isopropylacrylamide) gel, the reaction solution is transferred into freeze polymerization after pre-polymerization, so that mutually continuous ice crystal regions can be formed, and pores are left after the poly(N-isopropylacrylamide) gel is thawed at room temperature, therefore, a mutually penetrating open-celled pore structure can be formed, specific surface area of the prepared gel is greatly increased, diffusion resistance of water molecules is small, swelling/deswelling rate of the gel can be improved, and temperature response rate of the gel can be significantly improved.

Disclosed is a strain-monitoring damaged cable centralized load generalized displacement recognition method. The strain-monitoring damaged cable centralized load generalized displacement recognition method is based on strain monitoring. Whether a mechanical calculation reference model of a cable structure needs updating or not is determined through monitored cable structure temperature and environment temperature, and the mechanical calculation reference model, where the cable structure temperature and the environment temperature are reckoned, of the cable structure is acquired. A unit damage monitored amount numerical value variation matrix is acquired on the basis of the model. The non-inferior solution of an evaluated object current name damage vector is worked out according to the approximate linear relation between a monitored amount current numeric vector and a monitored amount current initial numerical value vector, the unit damage monitored amount value variation matrix and the evaluated object current name damage vector to be worked out. Accordingly, when temperature changes, a support generalized displacement, centralized load variable quantity and a damaged cable can be recognized.

The invention discloses a bridge structure temperature field monitoring method. The method comprises the following steps: S1, respectively calculating convective heat transfer and radiant heat transfer by utilizing an actually measured air temperature and a real-time air speed; S2, calculating solar radiation by utilizing the daily ordinal number and the solar radiation on the horizontal plane; S3, calculating a thermal boundary condition of the bridge according to the convective heat transfer, the radiant heat transfer and the solar radiation; S4, determining a heat exchange model of the bridge according to the thermal boundary condition of the bridge; and S5, solving the heat exchange model of the bridge by utilizing finite element numerical simulation to obtain a temperature field of the bridge, and completing monitoring of the temperature field of the bridge structure. The method does not need to depend too much on actually measured temperature data, only needs to install meteorological stations including temperature sensors, wind speed sensors and a total radiometer at a bridge site, and suggests that a few temperature sensors are installed on a bridge and model parameters areadjusted during initial use; cost is low and installation and usage are convenient; the monitoring range is wide, and full-bridge temperature monitoring can be realized.

The invention discloses a thermoset coupling structure dynamics order reduction model method suitable for thermodynamic elasticity analysis and belongs to the technical field of aerodynamics. The method comprises the steps of S1, performing order reduction on a structure temperature field, constructing a structure temperature field order reduction model, and obtaining a structure temperature fieldlow-order vector after order reduction of the structure temperature field at any moment; S2, selecting a modal shape of a reference structure as a reference modal shape phi ref, and performing orderreduction on a deformation field to obtain a low-dimensional vector q based on phi ref; s3, establishing a kinetic equation of the heated structure; s4, establishing a thermosetting coupling kinetic model of the heated structure; sampling is carried out in the q and the formed L + N-dimensional space; a series of sample working conditions with different deformation field and temperature field loads are obtained, M, D and K (1) in a formula (7) are identified through a system, and nonlinear structure dynamics analysis under a time-varying temperature load is carried out after training is completed, so that a thermosetting coupling dynamics model based on a neural network is a nonlinear model and has generality.

The present invention belongs to the field of the temperature measurement technology, and specifically relates to a nozzle section chamber wall temperature gradient measurement module of a liquid-propellant rocket engine combustion chamber. The module provided by the invention has an annular structure, and comprises an annular pressure plate, five thermocouple sensors, springs, separation blades, heat insulation linings and support sleeves. A disc-shaped separation blade is welded at each thermocouple sensor, one end, at the upper portion of the separation blade, of the each thermocouple sensor passes through a support sleeve and a spring, the support sleeves are sleeved with the springs and sleeved with the annular pressure plate, and the portions, below the separation blades, of the thermocouple sensors penetrate into the heat insulation linings. According to the invention, the temperature of the inner wall structure of the cooling channel in a cross section of the combustion chamber nozzle section may be measured, so that the parameters such as heat flow, gas wall temperature and outer wall temperature at the local place may be obtained.

The invention discloses a concrete crack control construction method with a jump warehouse method combined with an expansion reinforcing band. A post-cast strip of an ultra-large area basement is constructed, the jump warehouse method is adopted for achieving spaced construction, and the expansion concrete reinforcing band (9) with the concrete strength level improved by one level compared with the common concrete (11) is arranged between two adjacent bins; an expansion agent is doped into the expansion concrete reinforcing band (9). The construction method combining the jump warehouse methodwith the expansion reinforcing band avoids post-cast strip work, a large amount of working procedures of concrete post-cast strip shale chiseling, garbage cleaning, post-cast strip supporting and thelike can be reduced, the hidden danger of waterproof construction of the ultra-large area basement for control leakage can be reduced, meanwhile, basement waterproof and earthwork backfilling construction can be carried out in advance, and the structural temperature difference crack resistance is facilitated.

The invention discloses a high-precision fluid-solid coupling calculation method for a thermal environment of a head cone of a hypersonic flight vehicle. A flow field is discretized through a finite volume method, a structure temperature field is discretized through a finite element method, and coupling calculation is divided into inner iteration and outer iteration; internal iterative computationis repeatedly performed in any time step until the flow field and the structure temperature field converge or reach the maximum internal iterative step number, and the internal iteration is jumped out to enter the external iterative computation, so as to solve the next time step. According to the method, a result irrelevant to the time step length can be obtained under the large time step length,accumulated errors of a traditional fluid-solid coupling calculation method in the time advancing process can be eliminated, the problem of time lag existing in the traditional fluid-solid coupling calculation method is solved, and higher time precision is achieved. The calculation method has the advantages of being easy to understand, convenient to program and high in precision, and has universality for thermal environment coupling calculation of hypersonic flight vehicle components.

The invention discloses a pre-twisted wire breakage contact resistance experimental measuring method based on thermoelectric conversion. The method comprises the following steps: obtaining an accuratethermal parameter by calculation; according to the thermoelectric analogy theory and the temperature heat balance principle, establishing a heat circuit model for a ground wire and the pre-twisted wire fracture; designing a temperature rise experiment to obtain the temperature distribution of discrete points in the axial direction of the ground wire and the pre-twisted wire fracture; according tothe established heat circuit model and the temperature distribution of discrete points obtained by the temperature rise experiment, calculating the contact resistance of the ground wire and the interior of the pre-twisted wire fracture. The method of the invention obtains the AC contact resistance, can effectively avoid the magnetic field interference encountered by an electrical measurement method, only needs to detect the temperature distribution of discrete points of the overall structure, does not need to detect the impedance angle for the detection of AC resistance, requires less apparatus, facilitates online monitoring, and has significance of universal promotion and use.

The invention discloses a progressive identifying method for damaged cable concentrated loads and support angular displacement based on angle monitoring. The progressive identifying method determines whether the mechanical calculation reference model of a cable structure needs to be updated or not based on the angle monitoring through monitoring cable structure temperature and environmental temperature, so that a mechanical calculation reference model, considering the cable structure temperature and the environmental temperature, of the cable structure is obtained. On the basis of the model, a unit damage monitored angle numerical value change matrix is obtained through calculation. According to the approximate linear relation existing between the current numerical value vector of monitored angles and the current initial numerical value vector of the monitored angles, the unit damage monitored angle numerical value change matrix and a current evaluated object nominal damage vector to be solved, the non-inferior solution of the current evaluated object nominal damage vector is calculated, and therefore when temperature changes happen, the support angular displacement, the variable quantity of the concentrated loads and a damaged cable can be identified.

The invention discloses a hybrid-monitoring progressive identification method for a damaged cable and concentrated loads. On the basis of hybrid monitoring, whether a mechanical calculation reference model of a cable structure needs to be updated or not is determined by monitoring temperature of the cable structure, environment temperature, change degree of the concentrated loads and damage degree of the damaged cable, a new mechanical calculation reference model of the cable structure taking the change degree of the concentrated loads, the damage degree of the damaged cable and the temperature into consideration is obtained, on the basis of the model, according to the approximate linear relation between current numeric vectors of monitored quantities, current initial numeric vectors of the monitored quantities, a numerical value changing matrix of unit damage monitored quantities, and current nominal damage vectors to be solved, influences of interference factors can be eliminated when the temperature changes, and the damaged cable and variable quantities of the concentrated loads can be identified accurately.

The invention relates to an angular displacement strain monitoring identification method for a defective cable and concentrated loads. On the basis of strain monitoring, whether a mechanical calculation reference model of a cable structure needs to be updated or not is determined by monitoring the angular displacement of a supporting base, the temperature of the cable structure and environment temperature, a mechanical calculation reference model of the cable structure taking the angular displacement of the supporting base, the temperature of the cable structure and the environment temperature into account is obtained, and a value change matrix of unit damage monitored quantities is obtained through calculation on the basis of the model. According to the approximate linear relations between the current numeric vectors of the monitored quantities and the current initial numeric vectors of the monitored quantities, the value change matrix of the monitored unit damage quantities and the current nominal damage vectors of evaluation objects to be solved, the non-inferior solution of the current nominal damage vectors of the evaluation objects is calculated out. Accordingly, the effects of interference factors can be eliminated when the angular displacement of the supporting base and the temperatures change, and the variable quantities of the concentrated loads and the defective cable can be identified.

The invention discloses an identifying method for a damaged cable and concentrated loads based on space coordinate monitoring in time of angular displacement. The identifying method determines whether the mechanical calculation reference mode of a cable structure needs to be updated or not based on the space coordinate monitoring through monitoring the support angular displacement, cable structure temperature and environmental temperature, so that a mechanical calculation reference mode, considering the support angular displacement, the cable structure temperature and the environmental temperature, of the cable structure is obtained. On the basis of the model, a unit damage measured coordinate numerical value change matrix is obtained through calculation. According to the approximate linear relation existing between the current numerical value vector of monitored coordinates and the current initial numerical value vector of the monitored coordinates, the unit damage monitored coordinate numerical value change matrix and a current evaluated object nominal damage vector to be solved, the non-inferior solution of the current evaluated object nominal damage vector is calculated, and therefore when the support angular displacement and temperature changes happen, influences of interference factors can be removed, and the variable quantity of concentrated loads and the damaged cable can be identified.

The invention relates to a damaged cable identification method used in case of the angular displacement of a support and the temperature variation on the basis of the space coordinate monitoring. According to the damaged cable identification method, on the basis of the space coordinate monitoring, the angular displacement of the support, the temperatures of cable structures and the environment temperature are monitored to determine whether a mechanical calculation reference model of the cable structures needs to be updated, so as to obtain a mechanical calculation reference model of the cable structures, in which the angular displacement of the support, the temperatures of the cable structure and the environment temperature are counted; on the basis of the new model, a change matrix of a unit damage monitored quantity is obtained by calculation; and according to an approximate linear relation between a current value vector of the monitored quantity and a current initial value vector of the monitored quantity, the change matrix of the unit damage monitored quantity, a unit damage scalar and a current nominal damage vector to be obtained of a cable system, a noninferior solution of the current nominal damage vector of the cable system is calculated, so that when the support has the displacement and the temperature is changed, the positions and the damage degrees of damaged cables can be accurately determined.

The invention discloses a progressive identification method for slack cables based on hybrid monitoring of angular support displacement and temperature change. The progressive identification method can be used for deciding whether to update a mechanical calculation reference model of a cable structure through monitoring angular support displacement, a cable structure temperature, an environment temperature and a heath degree of a support cable. A noninferior solution of a current nominal damage vector is rapidly figured out according to an approximate linear relationship existing among a current value vector of a monitored quantity, a current initial value vector of the monitored quantity, a unit damage monitored quantity change matrix and a to-be-solved current nominal damage vector and by virtue of a multi-objective optimization algorithm and the like, therefore, virtual damaged cables can be identified when the angular support displacement and the temperature change exist, and after an actual damaged cable is identified by methods of nondestructive testing and the like, remained virtual damaged cables are the slack support cables; and the to-be-regulated cable lengths of the slack support cables can be determined according to a mechanical equivalent relationship.

A generalized displacement identification method for temperature variation hybrid monitored problem cables and supports is based on hybrid monitoring. Whether a mechanical calculation reference model of a cable structure requires to be updated is determined by monitoring cable structure temperature and environment temperature, a mechanical calculation reference model of a cable structure recording the cable structure temperature and the environment temperature is obtained, and a unit damage monitored quantity unit change matrix is obtained on the basis of the model. According to approximate linear relation between monitored quantity current numerical value vector and monitored quantity current initial numerical value vector, the unit damage monitored quantity unit change matrix, unit damage or unit generalized displacement vector and estimated object current name damage vector to be calculated, non-inferior solution of estimated object current name damage vector is calculated, so that generalized displacement of damaged cables, loosened cables and supports can be identified fast when temperature changes.

The invention discloses a damaged cable and support generalized displacement identification method based on strain monitoring of temperature change. The method comprises the following steps of: on the basis of strain monitoring, judging whether a mechanical calculation reference model of a cable structure is required to be updated by monitoring the temperature of the cable structure and environment temperature, and thus obtaining the mechanical calculation reference model of the cable structure, into which the temperature of the cable structure and the environment temperature are recorded; and on the basis of the mechanical calculation reference model, acquiring a unit damage monitored amount unit change matrix by calculation. A non-inferior solution of the current nominal damage vector of an evaluated object is obtained by calculation according to an approximately linear relationship between the current value vector of monitored amount, the current initial value vector of the monitored amount, the unit damage monitored amount unit change matrix, a unit damage or unit generalized displacement vector and the to-be-obtained current nominal damage vector of the evaluated object, so support generalized displacement and a damaged cable can be quickly identified by using an appropriate algorithm such as a multi-target optimization algorithm when the temperature change occurs.