Optimization Design of Metal Structures Based on Structural Functional Derivative Coefficients - Application Analysis of Manual Gourds

1. Core definition of Structural Functional Derivative Coefficient (SFDC)

Conceptual essence: In a structural functional coupling system, SFDC quantifies the impact trend of design parameters (such as size, material properties) on structural strength/performance through mathematical models. It establishes a derivative coefficient matrix through orthogonal experiments, variance analysis, and response surface methodology to reflect the sensitivity of parameter changes to key indicators such as redundancy strength and fatigue life.

Theoretical framework: including three dimensions: structural influence factor matrix (revealing the coupling law between structures), structural functional derivative coefficient (analyzing the trend of parameter influence), and structural functional coupling system (overall optimization strategy). For example, by fitting a redundant strength function

R=f(xone, xtwo, …)

The optimal combination of parameters such as main journal diameter and connecting rod journal diameter can be determined.

2. Optimization design path for metal structure of manual hoist

Material and process innovation:

High strength alloy steel: Using exclusive formula alloy steel, it undergoes double stage heat treatment of "isothermal quenching+low-temperature tempering", with a tensile strength exceeding 800MPa and a 60% improvement in wear resistance (such as Chenghua chain hoist chain wear of only 0.2mm/3000 hours, far below the industry standard of 1.5mm).

Hook and shell: The integral forged steel hook (with a breaking force of 5 times the rated load) and HT200 high-strength cast iron shell (with a wall thickness error of ≤ 0.5mm and an impact strength of 120kJ/m ²) are suitable for complex working conditions such as mining and construction.

Structural strength optimization:

Redundancy strength design: Through SFDC analysis, set a redundancy strength threshold (such as supporting multi lifecycle use when R ≥ 1.25), and prioritize optimizing sensitive parameters (sensitivity>20%). For example, the optimization interval for spindle neck diameter is 1mm, and the optimization interval for fillet radius is 0.2mm, ensuring that parameter adjustments cause significant strength changes.

Lightweight design: The main beam accounts for 40% -60% of the weight of the crane. Through box beam/I-beam section optimization, combined with finite element analysis to reduce material redundancy, a balance between weight and stiffness is achieved.

Security device upgrade:

Braking system: Double pawl interlocking structure (braking response time ≤ 0.3 seconds, sliding amount ≤ 5mm, better than the national standard of 15mm), friction plate brake prevents heavy objects from falling freely through self-locking mechanism.

Intelligent protection: Overload protection device (automatically cuts off power when the load exceeds 10%), height limit infrared induction, emergency switch and isolation switch, in compliance with CE/CMA certification standards.

3. Optimization design methodology and case studies

Mathematical Modeling and Simulation:

Using multiple linear regression and response surface methodology to fit the redundant strength function, such as

R1=12918.7−255.684x1+…

Analyze parameter coupling effects through Matlab to avoid high-order fitting oscillations.

The derivative coefficient derivative matrix (DCM ') quantifies the rate of parameter change and guides the parameter optimization step size (such as x ₁ optimization interval 1mm, x ∝ optimization interval 0.2mm).

Empirical case:

Chenghua chain hoist: By optimizing the chain, hook materials, and braking system through SFDC, it achieves 1000 cycles of braking without faults, with an effective triggering rate of 100% for safety protection devices, and is suitable for multi specification scenarios ranging from 0.5 tons to 100 tons.

Intelligent chain hoist: Equipped with high-precision sensors and handheld controllers, it achieves real-time monitoring of heavy object weight and speed, as well as uniform descent control, solving the technical bottleneck of traditional "can only go up, cannot go down".

4. Implementation points and standards

Design specifications: Follow the "Code for Acceptance of Welding of Pressure Pipelines" to ensure that the welding points are stress free and the grooves are smooth; During operation, heavy objects should be perpendicular to the vertical line of the hook, and diagonal pulling or overloading is prohibited.

Maintenance: Regularly check the lubrication status of the chain and gears (apply rust proof grease), the cleanliness of the brake friction surface, and conduct a comprehensive disassembly inspection and dynamic load test at least once a year.

Safety standards: Compliant with the standards of the National Quality Supervision and Inspection Center for Lifting and Transportation Machinery, and certified internationally (such as CE) to ensure the safety of high-altitude operations.

The main equipment produced by Hebei Makita: stage electric hoist, electric chian hoist, wire rope electric hoist，Hand chain hoist, lever hoist, pneumatic hoist and other lifting equipment