A parameter design method and system for a heavy bottom drive sliding door based on dynamic mechanics

Abstract

The application discloses a heavy bottom-driven sliding door parameter design method and system based on dynamics, and the method comprises the following steps: extracting the geometric inertia, material physical properties and motion control boundary parameters of the sliding door body, decoupling the running working condition stage, constructing a spatial shear stress distribution model and an alternating fatigue stress model in the start-up acceleration stage and the uniform speed running stage respectively, taking the safety factor and the fatigue limit as the convergence conditions, inversely solving and outputting the main frame profile wall thickness gradient function and the internal reinforcing rib asymmetric ratio parameter, inputting the parameters into a digitized base skeleton to perform entity finite element reconstruction, and comparing the stiffness by capturing the maximum transient deviation displacement amount of the top virtual displacement monitoring node under the extreme load, increasing the safety factor to recalculate if the comparison fails, and converting the comparison into a process processing control instruction if the comparison succeeds.

Description

Technical Field

[0001] This invention relates to the field of special doors and windows manufacturing, specifically to a method and system for designing parameters of heavy-duty bottom-drive sliding doors based on dynamic mechanics. Background Technology

[0002] With the rapid development of modern industrial buildings, special hangars, and tall logistics warehousing facilities, heavy-duty sliding doors with ultra-large spans and ultra-high tonnages have been widely used. Due to their massive size, these doors typically employ a bottom-point drive system to reduce the load on the top and simplify the upper track structure. This means that a drive motor, rack and pinion, or chain drive system installed at the bottom of the door propels it laterally along a ground track. However, traditional heavy-duty sliding doors often rely on static mechanics tables, crude safety factor additions, or uniform wall thickness designs based on engineering experience in their structural design and profile parameter selection. This traditional design approach presents the following problems when facing modern heavy-duty bottom-drive conditions: when the door accelerates from a standstill, the enormous motor thrust acts on the bottom of the profile, while the mass inertia of the door's tall body is concentrated at the upper-middle center of gravity. This causes the door to experience a large overturning moment in the translation plane, making the rectangular door prone to parallelogram shear deformation. Meanwhile, due to the eccentricity of the gate's center of gravity caused by localized locks and windows, the moment of activation is accompanied by a high-intensity out-of-plane torsional impact. Traditional uniform parameter designs cannot specifically reinforce this localized high-concentration stress, making the gate highly susceptible to frame weld cracking and permanent bending and torsional deformation of the skeleton under frequent activation. After heavy-duty gates pass through the acceleration phase and enter the uniform speed translation phase, the bottom pulleys or wheel sets require frequent reciprocating sliding for years or even decades. Due to the inevitable micro-unevenness of the ground track under long-term heavy-tonnage rolling, the wheel sets will transmit high-frequency alternating vibration and turbulence impacts to the bottom frame of the gate when passing through the track undulations at high speed. Traditional designs fail to incorporate this alternating fatigue life caused by the track's micro-unevenness into the calculation constraints, resulting in severe metal fatigue failure of the bottom longitudinal frame after tens of thousands of sliding cycles.

[0003] Therefore, in order to solve the problems existing in the prior art, this application proposes a parameter design method and system for heavy-duty bottom-drive sliding doors based on dynamic mechanics. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a method and system for designing parameters of heavy-duty bottom-drive sliding doors based on dynamic mechanics.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A parameter design method for heavy-duty bottom-drive sliding doors based on dynamic mechanics, comprising: The feature parameter extraction step involves constructing a three-dimensional coordinate system for the heavy-duty sliding door, extracting the geometric inertial feature parameters and material physical property parameters of the sliding door, and combining the dynamic response of the external drive motor to extract the motion control boundary parameters of the sliding door under operating conditions. The model construction steps involve decoupling the operating conditions of the sliding door body in stages based on the geometric inertial characteristic parameters, material physical property parameters, and motion control boundary parameters to obtain the start-up acceleration stage and the uniform speed operation stage. During the start-up acceleration stage, a shear stress distribution model is constructed, and during the uniform speed operation stage, an alternating fatigue stress model is constructed. The design parameter calculation steps take the preset safety factor and material fatigue limit as convergence boundary conditions, and the shear stress distribution model and alternating fatigue stress model as constraint inputs. The critical values ​​of the cross-sectional performance of the sliding door in different spatial height regions are calculated, and the non-uniform geometric dimension parameters of the door frame are output. The design parameter verification step involves inputting the output non-uniform geometric dimension parameters into the verification dynamic model for virtual reconstruction verification and outputting the verification result. When the verification result is passed, the non-uniform geometric dimension parameters are converted into process control commands.

[0006] As a further improvement of the present invention, the feature parameter extraction step includes: constructing a three-dimensional digital model of the sliding door and performing mass integration to extract the asymmetric centroid spatial coordinates of the model in the thickness direction; and calculating the spatial eccentricity between the centroid axis and the bottom drive axis based on the alignment of the asymmetric centroid spatial coordinates with the preset bottom drive axis.

[0007] As a further improvement of the present invention, the feature parameter extraction step further includes obtaining the transient start-up overload characteristic coefficient of the drive system, wherein the transient start-up overload characteristic coefficient represents the transient impact amplification effect caused by the mechanical clearance and elastic deformation of the drive components at the moment of motor start-up, and obtaining the dynamic friction coefficient curve of the bottom guide rail, wherein the dynamic friction coefficient curve is a nonlinear function that varies with the gate running speed.

[0008] As a further improvement of the present invention, the construction of the shear stress distribution model includes: combining the transient start-up overload characteristic coefficient and the rated thrust of the bottom drive motor to calculate the actual transient thrust acting on the lower edge of the door; deriving the transient overturning moment of the door frame in the translation plane and the transient torsional moment about the height axis based on the actual transient thrust, the centroid height of the door, and the geometric inertial characteristic parameters; and spatially coupling and projecting the transient overturning moment and the transient torsional moment to obtain the spatial shear stress distribution function along the main diagonal direction of the door.

[0009] As a further improvement of the present invention, the construction of the alternating fatigue stress model includes obtaining the micro-undulation function of the ground track, and calculating the vertical alternating excitation frequency of the door during its translation based on the uniform movement speed of the sliding door, and constructing the alternating cyclic stress amplitude function of the bottom longitudinal frame of the sliding door during the continuous translation process by combining the dynamic reaction force of the bottom guide wheel.

[0010] As a further improvement of the present invention, the design parameter calculation step includes the non-uniform geometric dimension parameters including the wall thickness gradient function of the main frame profiles around the sliding door body. The wall thickness gradient function specifies a non-linear decreasing law in which the wall thickness of the main profile gradually decreases with the increase of spatial height.

[0011] As a further improvement of the present invention, the non-uniform geometric dimension parameters also include the asymmetric ratio of the cross modulus of the cross reinforcing ribs inside the sliding door in the two operating directions. The asymmetric ratio parameters enable the two cross reinforcing ribs to use different cross-sectional moment of inertia dimensions, which can resist asymmetric torsional deformation when the sliding door starts in one direction.

[0012] As a further improvement of the present invention, the design parameter verification step further includes inputting the output non-uniform geometric dimension parameters into the verification dynamic model for finite element virtual reconstruction, adding extreme working condition loads, calculating the maximum displacement deformation of the diagonal at the top of the gate, and determining whether it is greater than a preset stiffness threshold. If it is greater than the preset threshold, the safety factor is increased, and the design parameter calculation step is re-executed.

[0013] As a further improvement of the present invention, the design parameter verification step further includes establishing a virtual displacement monitoring node at the top edge corner of the verification dynamic model, applying a rated transient thrust to the reconstructed three-dimensional solid form of the gate, simulating the dynamic process of the gate from rest to starting acceleration, calculating the dynamic bending and torsional deformation of the three-dimensional solid form of the gate under inertial lag conditions, capturing the maximum transient deviation displacement of the virtual displacement monitoring node in three-dimensional space in real time, and comparing the maximum transient deviation displacement with a preset stiffness threshold.

[0014] A parameter design system for a heavy-duty bottom-drive sliding door based on dynamic mechanics, comprising: The feature parameter extraction module constructs a three-dimensional coordinate system for the heavy sliding door, extracts the geometric inertial feature parameters and material physical property parameters of the sliding door, and extracts the motion control boundary parameters of the sliding door under the operating conditions by combining the dynamic response of the external drive motor. The model building module decouples the operating conditions of the sliding door in stages based on the geometric inertial characteristic parameters, material physical property parameters, and motion control boundary parameters, to obtain the start-up acceleration stage and the uniform speed operation stage. During the start-up acceleration stage, a shear stress distribution model is constructed, and during the uniform speed operation stage, an alternating fatigue stress model is constructed. The design parameter calculation module uses the preset safety factor and material fatigue limit as convergence boundary conditions, and the shear stress distribution model and alternating fatigue stress model as constraint inputs to calculate the critical values ​​of the cross-sectional performance of the sliding door in different spatial height regions, and outputs the non-uniform geometric dimension parameters of the door frame. The design parameter verification module inputs the output non-uniform geometric dimension parameters into the verification dynamic model for virtual reconstruction verification and outputs the verification result. When the verification result is passed, the non-uniform geometric dimension parameters are converted into process control commands.

[0015] The beneficial effects of this invention are as follows: The spatial shear stress distribution model constructed during the acceleration phase comprehensively considers transient overload, overturning, and eccentric torsional moments. Through spatial coupling projection and diagonal stress decomposition, the stress at nodes is quantified, providing a design basis for resisting deformation and cracking caused by inertial hysteresis. The alternating fatigue stress model constructed during the uniform velocity phase combines the micro-undulations of the track to calculate the vertical alternating excitation frequency and convert it into the internal cyclic stress amplitude, making the parameter solution comparable to the material fatigue limit and service life, providing design support for resisting long-term vibration damage. The profile wall thickness gradient function specifies the nonlinear decrease in wall thickness with height, storing stiffness at the bottom and reducing wall thickness at the top, lowering the center of gravity height and reducing the starting overturning moment; the asymmetric ratio parameter balances the asymmetric torsion during unidirectional start-up, achieving lightweighting. The system inversely assigns parameters to the reconstructed entity of the base skeleton, monitoring displacement through virtual nodes at the top under extreme loads. When the limit is exceeded, the safety factor is automatically increased and a recalculation is triggered, ensuring that the final converted process control commands pass simulation verification, guaranteeing the feasibility of the solution. Attached Figure Description

[0016] Figure 1 This is a flowchart of the parameter design for a heavy-duty bottom-drive sliding door according to the first embodiment of the present invention.

[0017] Figure 2 This is a flowchart of the parameter optimization and verification method of the present invention.

[0018] Figure 3 This is a block diagram of the parameter design system for a heavy-duty bottom-drive sliding door according to the third embodiment of the present invention. Detailed Implementation

[0019] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Identical components are denoted by the same reference numerals. It should be noted that the terms "front," "rear," "left," "right," "upper," and "lower" used in the following description refer to directions in the accompanying drawings, and the terms "bottom surface," "top surface," "inner," and "outer" refer to directions toward or away from the geometric center of a specific component, respectively.

[0020] The first embodiment of this invention proposes a parameter design method for heavy-duty bottom-drive sliding doors based on dynamic mechanics, such as... Figure 1 As shown, it includes: The feature parameter extraction step involves constructing a three-dimensional coordinate system for the heavy-duty sliding door, extracting the geometric inertial feature parameters and material physical property parameters of the sliding door, and combining the dynamic response of the external drive motor to extract the motion control boundary parameters of the sliding door under operating conditions.

[0021] The digital design system first obtains the basic external dimensions of the heavy-duty sliding door to be designed, including the overall length and height of the door, as well as the basic span of the main frame. The system then establishes a standard Cartesian three-dimensional coordinate system in the virtual design space. Typically, the direction of the door's length translation is designated as the first horizontal axis (X-axis), the direction of the door's height extension is designated as the second vertical axis (Y-axis), and the direction of the door's thickness perpendicular to the plane of movement is designated as the third transverse axis (Z-axis). After establishing the coordinate system, the system imports or constructs a three-dimensional digital skeleton model of the heavy-duty sliding door.

[0022] Because heavy-duty sliding doors, such as special industrial doors and large-span suspended sliding doors, are often composed of outer panels, internal asymmetrical reinforcing ribs, and local locks and seals, their mass distribution in the thickness direction is usually uneven.

[0023] The system accurately extracts the asymmetric centroid spatial coordinates of the door in the thickness direction, i.e., the third axis, by performing a mass integral calculation of the full spatial density of the three-dimensional digital model of the sliding door.

[0024] Subsequently, the system reads the preset bottom drive axis, which is the central physical plane where the drive motor and transmission rack are located, and aligns and compares the previously calculated asymmetric centroid spatial coordinates with this bottom drive axis. By calculating the spatial distance between the centroid axis and the bottom drive axis, the spatial eccentricity between the centroid axis and the bottom drive axis is obtained. This spatial eccentricity is the core basis for subsequent calculations of the torsional deformation of the door body around the axis.

[0025] The system extracts the inherent physical property parameters of the metal profiles used to construct the sliding door frame and reinforcing ribs, such as specific types of aluminum alloys or structural steel, from a digital material database. These parameters include at least: the material's elastic modulus, characterizing the profile's resistance to elastic deformation; shear modulus, characterizing the profile's stiffness under diagonal shear loads; Poisson's ratio; material density; and, most importantly, the material fatigue limit, serving as the stress convergence boundary for preventing fatigue failure of the door during long-term operation.

[0026] The gate is not in a static state under actual operating conditions; the response characteristics of the drive motor and the microscopic state of the track determine the dynamic boundaries. This step further extracts the following motion control boundary parameters: The acquisition of the transient start-up overload characteristic coefficients includes obtaining the dynamic response curve of the external drive motor connected to the system. Due to the significant transient current overload at startup, and the unavoidable mechanical clearances between drive components such as the drive chain or gears, coupled with the elastic deformation of the transmission system, the motor generates an impact force on the door body at startup that is much greater than that during the constant-speed operation phase. The system extracts the transient start-up overload characteristic coefficients to characterize this transient impact amplification effect.

[0027] The acquisition of the dynamic friction coefficient curve involves understanding that the frictional resistance between the pulley at the bottom of the gate and the ground guide rail changes dynamically at different operating stages. The system acquires the dynamic friction coefficient curve of the bottom guide rail, which is a nonlinear function that changes with the gate's operating speed. This curve accurately reflects the dynamic evolution of the bottom resistance as the gate transitions from a stationary state, breaking through static friction, entering the acceleration stage, and then to the uniform speed operating stage.

[0028] Through the above steps, the system successfully completed the initial extraction of multi-dimensional, multi-physics field feature parameters, transforming the gate structure and driving environment in the physical world into digital feature parameters that the system can recognize, laying a solid foundation for the construction of the decoupling model in the next stage.

[0029] The model construction steps involve decoupling the operating conditions of the sliding door in stages based on the geometric inertial characteristic parameters, material physical property parameters, and motion control boundary parameters, resulting in a start-up acceleration stage and a constant speed operation stage. During the start-up acceleration stage, a shear stress distribution model is constructed, and during the constant speed operation stage, an alternating fatigue stress model is constructed.

[0030] In this step, the digital design system, based on the multi-dimensional multi-physics discrete dataset obtained in the aforementioned feature parameter extraction step, decouples the complete operation process of the sliding door in multiple stages, specifically addressing the unique bottom single-point drive and overall inertial lag characteristic of heavy-duty sliding doors. The system establishes different mechanical equilibrium equations for the start-up acceleration stage and the uniform speed operation stage, thereby constructing a dual dynamic evaluation system composed of a spatial shear stress distribution model and an alternating fatigue stress model. In this embodiment, the shear stress distribution model is essentially a three-dimensional spatial function expression. This model uses the door's coordinates on the X, Y, and Z axes as input variables, and outputs the magnitude of the shear stress at each coordinate node. When this model is used as a constraint input, the algorithm essentially sets an inequality rule, requiring that the shear stress output value at any spatial coordinate point (x, y, z) calculated by this model must be strictly less than or equal to the allowable stress threshold after reducing the material fatigue limit. Once the algorithm pre-simulation detects that the stress at a certain coordinate exceeds the constraint range, the system will refuse to output the current parameters and trigger a redistribution of the wall thickness. The specific implementation process includes the following sub-steps: After receiving the control signal from the gate's stationary state to its closed or open state, the digital design system decouples the gate's physical motion from the time domain into two core stages based on the dynamic response curve of speed versus time: the acceleration phase, defined as the transient time window during which the gate accelerates from a stationary state with zero speed to a preset rated operating speed under the transient thrust of the drive motor, overcoming static friction; and the steady-state operation phase, defined as the steady-state time window during which the gate maintains a constant speed and performs reciprocating sliding motion on the track after reaching the preset rated operating speed. This decoupling overcomes the shortcomings of traditional designs that staticize and average the operating load, enabling precise capture of the gate's force characteristics under different motion states.

[0031] During the acceleration phase, the heavy-duty sliding door, due to its massive size and height, experiences severe asynchrony in its dynamic response as the driving force acts only at a single point on the bottom of the profile. The system reads the rated thrust of the bottom drive motor and multiplies it by the transient start-up overload characteristic coefficient obtained in the previous steps. This calculation takes into account the power amplification effect caused by mechanical clearance and transmission elastic deformation, thus obtaining the actual transient thrust acting on the lower edge of the door at the moment of start-up. Since the actual transient thrust is applied at the bottom of the profile, while the overall mass inertial hysteresis of the door is concentrated at the height of the door's center of mass, these two forces form a set of misaligned parallel shear forces in space. The calculation system derives the transient overturning moment in the translational motion plane by multiplying the actual transient thrust by the height of the door's center of mass. This moment physically tends to cause the door to tilt diagonally along the direction of travel, causing the rectangular door to deform into a parallelogram. Considering the deviation of the center of mass axis caused by the asymmetry of the local structure of the heavy-duty door, the calculation system further combines the spatial eccentricity calculated in the previous steps. The system derives the transient torsional moment about the axis of the door's height by multiplying the actual transient thrust by the lateral spatial eccentricity. This moment physically tends to cause the door to sway laterally and twist out of plane at the moment of activation.

[0032] The calculation system performs a three-dimensional spatial coupling projection of the transient overturning moment and the transient torsional moment. Combining the total height and length of the gate, the system calculates the main diagonal tilt angle of the gate and discretizes the coupled moments along this main diagonal direction and at the spatial coordinate points of the frame, thereby constructing and deriving a spatial shear stress distribution function that reflects the shear stress state at any coordinate point of the gate's spatial frame. This function serves as a rigid constraint for subsequent evaluation of the gate's starting stiffness.

[0033] In this embodiment, the shear stress distribution model is a three-dimensional spatial gradient matrix function. The actual transient thrust acting on the lower edge of the door is calculated as F. actual =F rated ×μ overload Among them, F actual For real-time transient thrust, F rated For the rated thrust of the bottom drive motor, μ overload The characteristic coefficient for the extracted transient start-up overload is typically set between 1.2 and 1.8, and is a dimensionless value derived from experience, used to represent the mechanical amplification effect caused by gear backlash and elastic deformation. The transient overturning moment M of the gate frame in the translation plane is calculated. overturn With the transient torque M about the height axis torsion There is M overturn =F actual ×H center M torsion =Factual ×e space , where H center To extract the height of the centroid of the gate, e space To determine the spatial eccentricity of the center of mass axis from the bottom drive axis, the system uses its internal 3D modeling engine to assign actual material density to the imported 3D digital skeleton model of the door, and then automatically extracts the output geometric coordinate difference using a full-space mass integration algorithm. After calculation, the constructed spatial shear stress distribution model function expression is: ; Because heavy-duty sliding doors, under bottom-drive conditions, are prone to parallelogram shear deformation along their diagonals due to the rectangular frame, this formula linearly superimposes the bending normal stress component generated by overturning with the torsional shear stress component generated by eccentricity, and multiplies it by cos(θ). diag This precisely projects the composite stress onto the main diagonal direction that causes the door deformation. Among these, Let I be the transient shear stress at the spatial coordinate point (x,y,z) of the door body. z Let I be the moment of inertia of the cross section about the transverse axis. p Let represent the polar moment of inertia, and represent the moment of inertia and polar moment of inertia of the profile section about the horizontal axis at the height coordinate y, respectively. These are calculated in real-time by the digital system from the geometric topology data of this section during finite element virtual reconstruction. x is the lateral distance from the target coordinate node to the central axis, and r is the distance from the node to the center of torsion. Let be the tilt angle of the main diagonal of the gate. When the model is used as a constraint input, the system iterates through all spatial coordinate nodes on the gate skeleton mesh, forcing the stress value of each node obtained by the above function to meet the following conditions. Where [τ] is the allowable shear stress of the material after being reduced by a preset safety factor. If an over-limit node is found, the algorithm will adaptively increase the wall thickness input value of the main profile within the height range until the equation is satisfied.

[0034] Once the gate has passed the acceleration phase and entered the constant speed operation phase, the inertial impact disappears, and the thrust of the drive motor is mainly used to overcome the frictional resistance of the ground track. However, because heavy gates need to slide back and forth frequently for years or even decades, the ground track will inevitably have microscopic undulations and unevenness under long-term load.

[0035] The system reads a preset function of the micro-undulations of the ground track. When the sliding door moves at a set uniform speed, the bottom rolling pulleys or guide wheels quickly pass over the uneven track surface. The calculation system divides the door's uniform speed by the characteristic wavelength of the track's micro-undulations to calculate the vertical alternating excitation frequency experienced by the door during translation. This frequency reflects the high-frequency impact from the ground that the door experiences during sliding. The calculation system combines the dynamic reaction force fed back from the ground track to the wheel assembly by the bottom guide wheels as they pass over the track's micro-undulations, using this dynamic reaction force as a cyclic external load input. The system simulates the continuous vibration response of the door at this specific alternating excitation frequency, converting the external load into internal stress pulsations within the bottom frame, and thus constructing an alternating cyclic stress amplitude function for the longitudinal frame at the bottom of the sliding door during continuous translation. This function is used to quantitatively assess the accumulation of metal fatigue damage during long-term reciprocating sliding of the door.

[0036] The alternating fatigue stress model is a frequency-stress amplitude mapping function used to quantify microscopic vibrations. For long-term damage inside the metal, during the specific construction, the vertical alternating excitation frequency fv is calculated as follows: , where v constant The preset uniform speed of the gate, To pass The characteristic wavelengths of micro-undulations in the ground track acquired by sensors or standard maps are the average wavelength data calculated from on-site sampling scans of the actual construction track using a track flatness detector or laser profilometer. Combining the gate's mass and spring damping coefficient, an alternating cyclic stress amplitude function for the bottom longitudinal frame during continuous translation is constructed. : ; This function transforms the high-frequency displacement excitation of the bottom pulley into a dynamic load in the form of a sinusoidal wave, and then divides it by the load-bearing cross-sectional area to obtain the amplitude of the pulsating alternating stress inside the bottom frame. Wherein, K... dynamic The dynamic amplification factor of the guide wheel system is obtained by referring to the empirical coefficients of the corresponding contact model in the mechanical design manual based on the material of the selected guide wheel and the contact stiffness of the track. m is the mass of the door body, g is the acceleration due to gravity, and A... bottom Given the current cross-sectional area of ​​the bottom longitudinal frame, the system transforms this external excitation into internal fatigue constraints. The system extracts the maximum peak value of the alternating cyclic stress amplitude function that varies with time, requiring it to be strictly lower than the fatigue limit value of this type of metal material obtained from the table, thereby meeting the fatigue resistance requirements of the gate.

[0037] Through decoupling modeling in this step, the system successfully transforms the two most destructive physical characteristics of heavy-duty bottom drive doors—instantaneous diagonal shear and torsion during startup and long-term high-frequency wheel-rail fatigue during operation—into two solvable mathematical stress functions, providing an indispensable input source for the inverse substitution solution of non-uniform geometric parameters in the next stage.

[0038] The design parameter calculation steps take the preset safety factor and material fatigue limit as convergence boundary conditions, and the shear stress distribution model and alternating fatigue stress model as constraint inputs. The critical values ​​of the cross-sectional performance of the sliding door in different spatial height regions are calculated, and the non-uniform geometric dimension parameters of the door frame are output.

[0039] In this step, the calculation system introduces a multi-dimensional convergence determination mechanism, using the spatial shear stress distribution model and alternating fatigue stress model generated in the aforementioned model construction steps as core constraint inputs. Simultaneously, the system retrieves a preset safety factor and material fatigue limit as convergence boundary conditions, and calculates the critical values ​​of the cross-sectional performance of the sliding gate frame in different spatial height regions through an internal numerical iterative optimization algorithm. Finally, the system concretizes the abstract mechanical performance requirements, reverse-engineers and outputs the non-uniform geometric dimensional parameters of the gate frame. Specifically, the system introduces a preset safety factor to safely reduce the yield strength of the material, obtaining the allowable stress threshold. The system uses the spatial shear stress distribution model as a direct strength constraint under accelerated start-up conditions, requiring that the maximum shear stress at each discrete node of the gate must not exceed this allowable stress threshold. The system introduces the material fatigue limit of the profile and correlates it with the preset total number of design operating life cycles of the gate for verification. The system uses the alternating cyclic stress amplitude function constructed during the uniform speed operation phase as a fatigue life constraint under continuous translation conditions, requiring that the cyclic stress amplitude borne by the bottom frame must be within the safe range of the material fatigue limit.

[0040] The system uses the aforementioned dual boundary conditions as the objective function and employs a reverse numerical iterative algorithm to solve the spatial topology of the gate layer by layer. Because the stress transfer from bottom to top under the bottom-driven condition of the gate exhibits significant decreasing characteristics and torsional asymmetry, the system does not calculate a globally uniform static performance index. Instead, it solves for the critical values ​​of the cross-sectional performance that each part of the profile must achieve in terms of structural stiffness for different spatial height regions of the gate, such as the high-stress zone at the bottom, the transition zone in the middle, and the low-stress zone at the top, as well as different force directions. These critical values ​​include, but are not limited to, the minimum cross-sectional moment of inertia and torsional section modulus of the profile.

[0041] In order to achieve lightweight structure and accurately counteract the risk of high deformation at the bottom of the gate caused by bottom drive, the system converts the critical values ​​of cross-sectional performance in different spatial height regions into non-uniform geometric dimension parameters of specific main frame profiles.

[0042] Specifically, such as Figure 1 As shown, the non-uniform geometric dimensional parameters include the wall thickness gradient function of the main frame profiles around the sliding door.

[0043] The wall thickness gradient function defines a non-linear decreasing law in which the wall thickness of the main profile gradually decreases with increasing spatial height. At the bottom of the gate, in the driving force zone, where the overturning moment and shear stress are at their maximum, the gradient function outputs a very large initial wall thickness to ensure the bottom frame has extremely high stiffness to resist bending and torsion. As the spatial height extends towards the top of the gate, the wall thickness output by the gradient function gradually decreases due to the non-linear decay of shear stress and bending moment, until it outputs the minimum preset wall thickness at the top. This non-uniform wall thickness design, which thins non-linearly with height, not only physically reduces the mass of the upper part of the gate and effectively lowers the overall center of gravity of the gate, thus reducing the overturning moment at startup, but also ensures that the material is precisely used in the areas of greatest stress.

[0044] In actual operation, the gate not only needs to open in one direction but also close in the opposite direction. When it starts in two different directions, due to the single-point drive bias of the motor and the eccentricity of the center of mass, the tensile shear and compressive shear states of the X-shaped diagonal reinforcing ribs intersecting inside the gate are different.

[0045] Specifically, such as Figure 1 As shown, the non-uniform geometric dimension parameters also include the asymmetric ratio of the cross modulus of the cross reinforcing ribs inside the sliding door in both the forward and reverse operating directions.

[0046] Based on the spatial shear stress evolution of the two diagonal stiffeners during leftward and rightward acceleration, the calculation system, through the aforementioned asymmetric ratio parameter, designes the two intersecting stiffeners with different cross-sectional moments of inertia and cross-sectional shapes. This asymmetric configuration of cross-sectional moments of inertia ensures that, regardless of whether the sliding door is in a forward or reverse unidirectional start-up moment, the stiffener on the side primarily subjected to tension or torsion possesses targeted anti-deformation stiffness. This maximizes resistance to the asymmetric bending and torsional deformation unique to bottom-drive sliding doors during unidirectional start-up without increasing the total weight of the steel inside the door.

[0047] Through the refined calculations in this step, the system successfully transformed the mechanical equations from the previous stage into a set of non-uniform, asymmetric gate frame size parameters with industrial customization features. This provides the core physical data for inputting these dimensions into the skeleton for closed-loop reconstruction verification in the next stage.

[0048] The design parameter verification step involves inputting the output non-uniform geometric dimension parameters into the verification dynamic model for virtual reconstruction verification and outputting the verification result. When the verification result is passed, the non-uniform geometric dimension parameters are converted into process control commands.

[0049] In this step, the computational system performs a real-world numerical reverse reconstruction of the geometric dimensional parameters, which exhibit non-uniform and asymmetric characteristics, output from the aforementioned design parameter calculation steps. By simulating the real dynamic behavior of the special gate under extreme working conditions, an adaptive optimization control closed loop is established. This step ensures that the final output manufacturing instructions possess 100% reliability in terms of stiffness and long-term durability. The specific implementation process includes the digital design system calling upon the digital base skeleton of the gate constructed in the initial stage. At this point, the base skeleton in the computer memory is merely a spatial wireframe topological mesh model without geometric thickness. The system performs a reverse assignment operation, using the wall thickness gradient function of the outer main frame profiles calculated in the aforementioned steps, and the asymmetric ratio of the section modulus of the internal cross stiffeners in both positive and negative operating directions, as geometric thickness features, and applying them to the corresponding spatial wireframe nodes and edges of the base skeleton.

[0050] Through this virtual reconstruction process, the system endows the originally abstract wireframe model with realistic local thickness and spatial topological cross-section in virtual space, thereby generating a three-dimensional solid form of the gate with realistic geometric thickness. This solid form can accurately reflect the physical characteristics of the gate, which is heavy at the bottom and light at the top, and has asymmetrical positive, negative, and torsional properties.

[0051] To accurately monitor the deformation of heavy-duty gates under bottom-drive impact, the system needs to capture the most sensitive and dangerous critical points of gate stiffness deformation. Specifically, the system establishes virtual displacement monitoring nodes at the top edge corners of the digital base frame of the gate. Due to the gate's height and the fact that the drive point is at the bottom, the far corner at the top is the physical location with the greatest cumulative inertial hysteresis deformation at the moment of startup. The system then applies predetermined extreme loads to the reconstructed three-dimensional solid form of the gate in a virtual simulation environment. The system not only applies the rated transient thrust generated by the bottom motor but also introduces external alternating disturbances such as maximum wind load, comprehensively simulating the complete dynamic process of the gate from complete stillness to instantaneous acceleration.

[0052] At the instant the extreme load is applied, due to the huge driving force applied to the bottom, and the inertial lag caused by its own mass in the upper part of the gate, there will be a tendency to sway, bend and twist out of plane in the opposite direction of operation.

[0053] The computing system activates the finite element dynamics analysis unit to calculate the dynamic bending and torsional deformation of the three-dimensional solid form of the gate under this inertial lag condition in real time. At the same time, the sensor module inside the system focuses on the aforementioned virtual displacement monitoring node, capturing and quantifying the maximum transient deviation displacement of the monitoring node from the original vertical equilibrium plane in three-dimensional space, that is, the maximum sway distance of the top corner of the gate.

[0054] The control system automatically compares and judges the maximum transient deviation displacement captured in real time with the preset stiffness threshold, i.e. the maximum safe sway of the gate, and executes different control branches according to the judgment result.

[0055] The first branch responds when the maximum transient deviation displacement is greater than or equal to the preset stiffness threshold. At this point, the system determines that the currently calculated profile wall thickness gradient and stiffener dimensions still result in excessive sway when the gate is instantly activated, and the structural stiffness cannot meet the safety requirements for long-term durability. The control system then initiates adaptive feedback control, automatically increasing the aforementioned safety factor by a preset adjustment step size. The system uses the updated, larger safety factor as the new convergence boundary, triggering the system to re-execute the design parameter calculation steps. The system recalculates the wall thickness gradient and asymmetry ratio using the increased safety factor and re-enters this step for reconstruction and virtual thrust verification. This process constitutes an automatic iterative loop until the displacement is compressed within a safe range.

[0056] The second branch responds when the maximum transient deviation displacement is less than the preset stiffness threshold. At this point, the system determines that the non-uniform geometric parameters of the current door have perfectly met the standards in terms of stiffness, strength, and fatigue life, and the structure possesses extremely high resistance to deformation and fatigue durability. The virtual verification is declared successful. The system then unlocks the data and executes the manufacturing instruction output, formally converting the current non-uniform geometric parameters, including the specific wall thickness dimensions of each segment and the shape of the reinforcing ribs, into process control instructions for the standard door and window manufacturing system. These control instructions are issued to the CNC cutting machine unit, variable wall thickness profile drawing unit, and automated welding robot in the production workshop to guide the precise customization and manufacturing of the physical sliding door.

[0057] This closed-loop verification process ensures the feasibility of licensing and the reliability of operation of heavy-duty bottom-drive sliding doors in the real physical world.

[0058] To further assure reviewers and those skilled in the art of implementing this solution, the data flow is illustrated using a heavy-duty bottom-drive sliding door of a specific size as an example: The sliding door is set to a total length of 15m and a total height of 5m. 6061 aluminum alloy is selected, and the allowable shear stress is preset to [τ] = 80MPa. The centroid height H is obtained from the digital model.center =2.5m, centroid eccentricity e space =0.15m. Rated thrust F of the motor rated =3000N, with a starting overload factor of 1.5. Using the shear stress distribution model, the transient thrust is calculated to be 4500N, and the transient overturning moment is 11250N·m. The system substitutes this load into the model and matches it with the safety constraint of 80MPa.

[0059] To meet the aforementioned stress constraints and achieve lightweight design, the system inversely solves and outputs the wall thickness gradient function of the main frame profiles around the door. In the high-stress zone (0-1.5m height), the output profile wall thickness is 12mm; in the medium-stress zone (1.5-3.5m height), the output profile wall thickness is 8mm; and in the low-stress zone (3.5-5m height), the output profile wall thickness is 5mm. Simultaneously, the asymmetric ratio of the section modulus of the positive tension stiffener is output as 1.4, which means the moment of inertia of the stiffener on that side is amplified by 40%. The above wall thickness parameters and the asymmetric ratio of 1.4 are input into the verification dynamic model. After applying a transient thrust of 4500N, the maximum transient deviation displacement of the top diagonal captured by the virtual displacement monitoring node is 18mm, which is less than the preset stiffness threshold of 25mm, indicating a successful verification. The system then converts the gradient wall thickness parameters (12mm-8mm-5mm) into process control commands for CNC drawing and cutting machine tools.

[0060] The second embodiment of this invention proposes a method for optimizing and verifying the parameters of a heavy-duty bottom-drive sliding door based on dynamic mechanics, such as... Figure 2 The diagram shows a further refinement and expansion of the core model building and verification steps in the first embodiment. The specific implementation process is as follows: Specifically, such as Figure 2 As shown, the construction of the shear stress distribution model includes: combining the transient start-up overload characteristic coefficient and the rated thrust of the bottom drive motor to calculate the actual transient thrust acting on the lower edge of the door; deriving the transient overturning moment of the door frame in the translation plane and the transient torsional moment about the height axis based on the actual transient thrust, the height of the door's center of mass, and the geometric inertial characteristic parameters; and spatially coupling and projecting the transient overturning moment and the transient torsional moment to obtain the spatial shear stress distribution function along the main diagonal of the door.

[0061] The system combines the transient start-up overload characteristic coefficient of the drive system obtained in the feature parameter extraction step with the rated thrust of the bottom drive motor, and calculates the actual transient thrust acting on the lower edge of the door by multiplying the two.

[0062] Since the actual transient thrust acts on the bottom of the gate, while the overall inertial hysteresis force of the gate acts at the height of the gate's center of mass, this physically causes the gate to tend to tilt forward or backward. Therefore, the calculation system derives the transient overturning moment of the gate frame in the translation plane based on the product of the actual transient thrust and the height of the gate's center of mass. Considering the spatial eccentricity caused by the asymmetric spatial coordinates of the gate's center of mass in the thickness direction, i.e., the center of mass of the gate does not fall precisely on the bottom drive axis, the actual transient thrust will also generate a transient torsional moment about the axis in the height direction of the gate. The system calculates this transient torsional moment by multiplying the actual transient thrust by the spatial eccentricity. The digital design system performs spatial coupling projection of the transient overturning moment and the transient torsional moment, and performs stress decomposition along the main diagonal angle of the gate, i.e., the arctangent diagonal angle of the total height and total length of the gate, deriving a spatial shear stress distribution function that reflects the shear stress state at any coordinate point of the gate's spatial frame.

[0063] Specifically, such as Figure 2 As shown, the construction of the alternating fatigue stress model includes obtaining the micro-undulation function of the ground track, calculating the vertical alternating excitation frequency of the door during its translation based on the uniform speed of the sliding door, and constructing the alternating cyclic stress amplitude function of the bottom longitudinal frame of the sliding door during the continuous translation process by combining the dynamic reaction force of the bottom guide wheel.

[0064] The system acquires the microscopic undulation function of the ground track during processing and installation. When the gate moves at a set uniform speed, the small vertical displacement excitation caused by the bottom pulley passing at high speed over the uneven track surface is converted into high-frequency bumping impact. The system calculates the vertical alternating excitation frequency experienced by the gate during translation based on the ratio of the uniform speed to the characteristic wavelength of the track's microscopic undulations. Furthermore, the calculation system combines the dynamic reaction force experienced by the bottom guide wheel when passing over the microscopic undulations to construct the alternating cyclic stress amplitude function of the longitudinal frame at the bottom of the sliding gate during continuous translation, which is used to evaluate the metal fatigue life of the gate under long-term reciprocating operation.

[0065] Specifically, such as Figure 2 As shown, the design parameter verification step further includes inputting the output non-uniform geometric dimension parameters into the verification dynamic model for finite element virtual reconstruction, adding extreme working condition loads, calculating the maximum displacement deformation of the diagonal at the top of the gate, and determining whether it is greater than a preset stiffness threshold. If it is greater than the preset threshold, the safety factor is increased, and the design parameter calculation step is re-executed.

[0066] The digital design system establishes a digital base skeleton for the door without geometric thickness, namely a spatial wireframe topological mesh model. The wall thickness gradient functions of the main frame profiles around the door, output from the design parameter calculation steps, and the asymmetric ratio parameters of the section modulus of the internal cross stiffeners in both positive and negative directions, are then applied to the base skeleton in reverse. This is equivalent to applying corresponding thickness dimensions to the wireframe model at different heights and directions. After reconstruction, a three-dimensional solid form of the door with realistic geometric thickness is obtained in virtual space.

[0067] To accurately monitor the maximum deformation of the gate under stress, the system establishes a virtual displacement monitoring node at the top edge corner of the digital base skeleton of the gate. This node serves as the most sensitive detection point for the gate's stiffness deformation. The system applies a rated transient thrust to the reconstructed three-dimensional solid form of the gate and simulates the complete dynamic process of the gate from rest to acceleration.

[0068] At this point, because the driving force is applied to the bottom, the top of the gate will tend to sway and twist backward due to inertial lag. The computing system begins to analyze the dynamic bending and torsional deformation of the three-dimensional solid shape of the gate under inertial lag conditions, and captures the maximum transient deviation displacement of the virtual displacement monitoring node in three-dimensional space in real time.

[0069] Specifically, such as Figure 2 As shown, the design parameter verification step further includes establishing a virtual displacement monitoring node at the top edge corner of the verification dynamic model, applying a rated transient thrust to the reconstructed three-dimensional solid form of the gate, simulating the dynamic process of the gate from rest to acceleration, calculating the dynamic bending and torsional deformation of the three-dimensional solid form of the gate under inertial lag conditions, capturing the maximum transient deviation displacement of the virtual displacement monitoring node in three-dimensional space in real time, and comparing the maximum transient deviation displacement with a preset stiffness threshold.

[0070] When the judgment result indicates that the maximum transient deviation displacement is greater than or equal to the preset stiffness threshold, it means that under extreme starting impact, the currently calculated profile wall thickness and reinforcing rib dimensions will cause excessive door shaking and insufficient structural stiffness. At this point, the control system automatically increases the safety factor, adding a preset adjustment step size to the original safety factor, and triggers the system to re-execute the design parameter calculation steps. The system will recalculate the wall thickness and reinforcing rib dimensions using the increased safety factor and re-enter the reconstruction verification stage until the maximum transient deviation displacement is less than the preset threshold. When the judgment result indicates that the maximum transient deviation displacement is less than the preset stiffness threshold, the current geometric stiffness of the door is deemed to meet the standard, and the verification is passed. The system then executes the manufacturing instruction output, converting the current non-uniform geometric parameters into process control instructions, which are sent to the variable wall thickness profile drawing unit and CNC cutting machine in the workshop for customized production of the physical door body.

[0071] The third embodiment of this invention proposes a parameter design system for heavy-duty bottom-drive sliding doors based on dynamic mechanics, such as... Figure 3 As shown, it includes: The feature parameter extraction module constructs a three-dimensional coordinate system for the heavy sliding door, extracts the geometric inertial feature parameters and material physical property parameters of the sliding door, and extracts the motion control boundary parameters of the sliding door under the operating conditions by combining the dynamic response of the external drive motor. The model building module decouples the operating conditions of the sliding door in stages based on the geometric inertial characteristic parameters, material physical property parameters, and motion control boundary parameters, to obtain the start-up acceleration stage and the uniform speed operation stage. During the start-up acceleration stage, a shear stress distribution model is constructed, and during the uniform speed operation stage, an alternating fatigue stress model is constructed. The design parameter calculation module uses the preset safety factor and material fatigue limit as convergence boundary conditions, and the shear stress distribution model and alternating fatigue stress model as constraint inputs to calculate the critical values ​​of the cross-sectional performance of the sliding door in different spatial height regions, and outputs the non-uniform geometric dimension parameters of the door frame. The design parameter verification module inputs the output non-uniform geometric dimension parameters into the verification dynamic model for virtual reconstruction verification and outputs the verification result. When the verification result is passed, the non-uniform geometric dimension parameters are converted into process control commands.

[0072] The foregoing has illustrated and described the basic features, principles, and advantages of the present invention. It should be noted that the present invention is not limited to the above embodiments, but only to some embodiments. Any improvements and additions made without departing from the spirit and scope of the present invention are considered to be within the scope of protection of the present invention.

Claims

1. A parameter design method for a heavy-duty bottom-drive sliding door based on dynamic mechanics, characterized in that, include: The feature parameter extraction step involves constructing a three-dimensional coordinate system for the heavy-duty sliding door, extracting the geometric inertial feature parameters and material physical property parameters of the sliding door, and combining the dynamic response of the external drive motor to extract the motion control boundary parameters of the sliding door under operating conditions. The model construction steps involve decoupling the operating conditions of the sliding door body in stages based on the geometric inertial characteristic parameters, material physical property parameters, and motion control boundary parameters to obtain the start-up acceleration stage and the uniform speed operation stage. During the start-up acceleration stage, a shear stress distribution model is constructed, and during the uniform speed operation stage, an alternating fatigue stress model is constructed. The design parameter calculation steps take the preset safety factor and material fatigue limit as convergence boundary conditions, and the shear stress distribution model and alternating fatigue stress model as constraint inputs. The critical values ​​of the cross-sectional performance of the sliding door in different spatial height regions are calculated, and the non-uniform geometric dimension parameters of the door frame are output. The design parameter verification step involves inputting the output non-uniform geometric dimension parameters into the verification dynamic model for virtual reconstruction verification and outputting the verification result. When the verification result is passed, the non-uniform geometric dimension parameters are converted into process control commands.

2. The method for designing parameters of a heavy-duty bottom-drive sliding door based on dynamic mechanics according to claim 1, characterized in that, The feature parameter extraction step includes constructing a three-dimensional digital model of the sliding door and performing mass integration to extract the asymmetric centroid spatial coordinates of the model in the thickness direction. Based on the alignment of the asymmetric centroid spatial coordinates with the preset bottom drive axis, the spatial eccentricity between the centroid axis and the bottom drive axis is calculated.

3. The method for designing parameters of a heavy-duty bottom-drive sliding door based on dynamic mechanics according to claim 1, characterized in that, The feature parameter extraction step further includes obtaining the transient start-up overload characteristic coefficient of the drive system, which represents the transient impact amplification effect caused by the mechanical clearance and elastic deformation of the drive components at the moment of motor start-up, and obtaining the dynamic friction coefficient curve of the bottom guide rail, which is a nonlinear function that varies with the gate running speed.

4. The method for designing parameters of a heavy-duty bottom-drive sliding door based on dynamic mechanics according to claim 1, characterized in that, The construction of the shear stress distribution model includes: combining the transient start-up overload characteristic coefficient and the rated thrust of the bottom drive motor to calculate the actual transient thrust acting on the lower edge of the door; deriving the transient overturning moment of the door frame in the translation plane and the transient torsional moment about the height axis based on the actual transient thrust, the height of the door's center of mass, and the geometric inertial characteristic parameters; and spatially coupling and projecting the transient overturning moment and the transient torsional moment to obtain the spatial shear stress distribution function along the main diagonal of the door.

5. The method for designing parameters of a heavy-duty bottom-drive sliding door based on dynamic mechanics according to claim 1, characterized in that, The alternating fatigue stress model is constructed by obtaining the micro-undulation function of the ground track, calculating the vertical alternating excitation frequency of the door during its translation based on the uniform speed of the sliding door, and constructing the alternating cyclic stress amplitude function of the bottom longitudinal frame of the sliding door during the continuous translation process by combining the dynamic reaction force of the bottom guide wheel.

6. The method for designing parameters of a heavy-duty bottom-drive sliding door based on dynamic mechanics according to claim 1, characterized in that, The design parameter calculation steps include the following: the non-uniform geometric dimension parameters include the wall thickness gradient function of the main frame profiles around the sliding door body. The wall thickness gradient function specifies a non-linear decreasing law in which the wall thickness of the main profile gradually decreases as the spatial height increases.

7. The method for designing parameters of a heavy-duty bottom-drive sliding door based on dynamic mechanics according to claim 1, characterized in that, The non-uniform geometric dimension parameters also include the asymmetric ratio of the cross modulus of the cross reinforcing ribs inside the sliding door in the two operating directions. The asymmetric ratio parameter allows the two cross reinforcing ribs to use different cross-sectional moment of inertia dimensions, which can resist asymmetric torsional deformation when the sliding door starts in one direction.

8. The method for designing parameters of a heavy-duty bottom-drive sliding door based on dynamic mechanics according to claim 1, characterized in that, The design parameter verification step also includes inputting the output non-uniform geometric dimension parameters into the verification dynamic model for finite element virtual reconstruction, adding extreme working condition loads, calculating the maximum displacement deformation of the diagonal at the top of the gate, and determining whether it is greater than a preset stiffness threshold. If it is greater than the preset threshold, the safety factor is increased, and the design parameter calculation step is re-executed.

9. The method for designing parameters of a heavy-duty bottom-drive sliding door based on dynamic mechanics according to claim 8, characterized in that, The design parameter verification step also includes establishing a virtual displacement monitoring node at the top edge corner of the verification dynamic model, applying a rated transient thrust to the reconstructed three-dimensional solid form of the gate, simulating the dynamic process of the gate from rest to acceleration, calculating the dynamic bending and torsional deformation of the three-dimensional solid form of the gate under inertial lag conditions, capturing the maximum transient deviation displacement of the virtual displacement monitoring node in three-dimensional space in real time, and comparing the maximum transient deviation displacement with a preset stiffness threshold.

10. A parameter design system for a heavy-duty bottom-drive sliding door based on dynamic mechanics, applicable to the parameter design method for a heavy-duty bottom-drive sliding door based on dynamic mechanics as described in any one of claims 1 to 9, characterized in that, include: The feature parameter extraction module constructs a three-dimensional coordinate system for the heavy sliding door, extracts the geometric inertial feature parameters and material physical property parameters of the sliding door, and extracts the motion control boundary parameters of the sliding door under the operating conditions by combining the dynamic response of the external drive motor. The model building module decouples the operating conditions of the sliding door in stages based on the geometric inertial characteristic parameters, material physical property parameters, and motion control boundary parameters, to obtain the start-up acceleration stage and the uniform speed operation stage. During the start-up acceleration stage, a shear stress distribution model is constructed, and during the uniform speed operation stage, an alternating fatigue stress model is constructed. The design parameter calculation module uses the preset safety factor and material fatigue limit as convergence boundary conditions, and the shear stress distribution model and alternating fatigue stress model as constraint inputs to calculate the critical values ​​of the cross-sectional performance of the sliding door in different spatial height regions, and outputs the non-uniform geometric dimension parameters of the door frame. The design parameter verification module inputs the output non-uniform geometric dimension parameters into the verification dynamic model for virtual reconstruction verification and outputs the verification result. When the verification result is passed, the non-uniform geometric dimension parameters are converted into process control commands.

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