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Geometric modeling : Build a three-dimensional model of the hook based on CAD software (such as SolidWorks, CATIA), which must include detailed features (threads, fillets, etc.).

Material properties : define material parameters (e.g. elastic modulus of alloy steel 210GPa, Poisson’s ratio 0.3, yield strength 690MPa).

Meshing :

• High-density mesh (size ≤ 2mm) is used in key areas (hook neck, thread).

• Non-critical areas can be appropriately sparse (size 5~10mm).

• Example: The mesh number of a 50t hook model is about 500,000 units (dominated by hexahedrons).

Constraints : Simulate actual installation and fix the top thread or pin connection surface of the hook.

Load application :

• Vertical load: Apply rated load (e.g. 500kN) to the bottom contact surface of the hook.

• Dynamic load: Simulate acceleration/emergency stop conditions through transient analysis (load factor 1.2~1.5).

• Eccentric load: an asymmetric force is applied to one side of the hook (angle 30°~60°).

Static analysis : calculate stress distribution and deformation (Figure 1).

Fatigue analysis : Predict cycle life based on SN curve and Miner's law.

Failure criteria :

• Maximum Von Mises stress < material yield strength (safety factor ≥ 4).

• The strain in the critical area is less than the allowable value (such as 0.2%).

Goal : To lose weight while maintaining sufficient intensity.

Method : Use variable density method (such as SIMP algorithm) and set constraint conditions (stress <500MPa, displacement <1mm).

Case : After optimization, a forged hook lost 15% of its weight and reduced stress concentration by 20%.

Parametric design : adjust the hook mouth curvature and hook neck transition radius (Figure 2).

Response surface methodology (RSM) : Establish a mathematical model of design variables (such as R1, R2) and stress response.

Results : After optimization, the peak stress at the hook mouth decreased by 30% (from 650MPa to 450MPa).

Alternative materials : 34CrNiMo6 is used to replace traditional 42CrMo (fatigue strength increased by 25%).

Composite materials : Carbon fiber reinforced local high stress areas (interface bonding performance needs to be considered).

Problem : Frequent cracks on the hook neck.

FEA found that the stress concentration at the root of the thread (up to 780MPa) exceeded the yield strength of the material (690MPa).

Optimization plan :

• Increase the thread transition radius (from R2→R5).

• Surface shot peening treatment.

Effect : Maximum stress is reduced to 520MPa and service life is extended by 3 times.

Initial design : 80t hook weight 320kg.

Topology optimization : removing material from non-load-bearing areas (Figure 3).

Result : Weight dropped to 270kg and static safety factor remained at 4.2.

Geometric modeling : Build a three-dimensional model of the hook based on CAD software (such as SolidWorks, CATIA), which must include detailed features (threads, fillets, etc.).

Material properties : define material parameters (e.g. elastic modulus of alloy steel 210GPa, Poisson’s ratio 0.3, yield strength 690MPa).

Meshing :

• High-density mesh (size ≤ 2mm) is used in key areas (hook neck, thread).

• Non-critical areas can be appropriately sparse (size 5~10mm).

• Example: The mesh number of a 50t hook model is about 500,000 units (dominated by hexahedrons).

Constraints : Simulate actual installation and fix the top thread or pin connection surface of the hook.

Load application :

• Vertical load: Apply rated load (e.g. 500kN) to the bottom contact surface of the hook.

• Dynamic load: Simulate acceleration/emergency stop conditions through transient analysis (load factor 1.2~1.5).

• Eccentric load: an asymmetric force is applied to one side of the hook (angle 30°~60°).

Static analysis : calculate stress distribution and deformation (Figure 1).

Fatigue analysis : Predict cycle life based on SN curve and Miner's law.

Failure criteria :

• Maximum Von Mises stress < material yield strength (safety factor ≥ 4).

• The strain in the critical area is less than the allowable value (such as 0.2%).

Goal : To lose weight while maintaining sufficient intensity.

Method : Use variable density method (such as SIMP algorithm) and set constraint conditions (stress <500MPa, displacement <1mm).

Case : After optimization, a forged hook lost 15% of its weight and reduced stress concentration by 20%.

Parametric design : adjust the hook mouth curvature and hook neck transition radius (Figure 2).

Response surface methodology (RSM) : Establish a mathematical model of design variables (such as R1, R2) and stress response.

Results : After optimization, the peak stress at the hook mouth decreased by 30% (from 650MPa to 450MPa).

Alternative materials : 34CrNiMo6 is used to replace traditional 42CrMo (fatigue strength increased by 25%).

Composite materials : Carbon fiber reinforced local high stress areas (interface bonding performance needs to be considered).

Problem : Frequent cracks on the hook neck.

FEA found that the stress concentration at the root of the thread (up to 780MPa) exceeded the yield strength of the material (690MPa).

Optimization plan :

• Increase the thread transition radius (from R2→R5).

• Surface shot peening treatment.

Effect : Maximum stress is reduced to 520MPa and service life is extended by 3 times.

Initial design : 80t hook weight 320kg.

Topology optimization : removing material from non-load-bearing areas (Figure 3).

Result : Weight dropped to 270kg and static safety factor remained at 4.2.