Which design performed best in this study?

Design F combines an 8 mm base plate, 12% rounded cutouts and longitudinal stiffeners on both sides. It scored 92.6/100 under the stated test conditions. Relative to the 8 mm solid-plate baseline, mass increased 1.4%, maximum deflection decreased 33.2%, peak stress decreased 11.3% and cyclic retention improved 5.1%.

How do stiffeners and cutouts work together?

Cutouts and stiffeners alter load paths and introduce stress concentrations at cutout edges, stiffener ends and weld toes. Design E shows that cutouts alone can increase deflection and reduce service-life performance. Place stiffeners where they improve bending resistance and remove material from low-demand regions while checking the load path and life requirements.

Is there a lower-cost alternative?

Design D (6 mm stiffened plate) is a cost-sensitive alternative. In this batch it had approximately 8.6% lower mass than the 8 mm solid-plate baseline, 16.1% lower maximum deflection and 2.6% better cyclic retention. It can be compared against alternatives for stations with strong initial-unit cost constraints and requirements for operating feel and cyclic retention, taking site conditions into account.

How were the prototypes tested and compared?

The study compared six designs A–F using 36 prototypes (6 × 6). Testing covered 1.5 kN static loading, dynamic positioning disturbances and 20,000 endurance cycles. Analysis used descriptive statistics, one-way ANOVA (P<0.05), linear regression with adjusted R²=0.939 for deflection, and a 100-point combined score.

What further work is required before design finalization?

The design cannot be finalized solely from these results. Endurance validation covered 20,000 cycles and used engineering-equivalent material parameters. Before finalization, complete finite-element hotspot checks, material-batch tests, weld-distortion compensation, site service-life and safety-risk validation, and issue formal company design documents, test reports and approval records.

Coordinated Lightweight Design of Main Load-Bearing Plate Thickness, Stiffeners and Cutouts for Custom Handling Tooling

Q: What further work is required before design finalization?

The design cannot be finalized solely from these results. Endurance validation covered 20,000 cycles and used engineering-equivalent material parameters. Before finalization, complete finite-element hotspot checks, material-batch tests, weld-distortion compensation, site service-life and safety-risk validation, and issue formal company design documents, test reports and approval records.

Key points of this article

Lightweight tooling design should redistribute material according to load paths and service-life limits, while controlling mass, stiffness and local stress. Plate thickness, stiffeners and cutouts must be designed together rather than independently maximizing thickness or material removal.
Compare six designs A–F using 36 prototypes, 1.5 kN static loading, dynamic disturbances and 20,000-cycle endurance tests. Analyze the results using analysis of variance, linear regression and a 100-point combined score.
In this test batch, design F (8 mm base plate + 12% rounded cutouts + longitudinal stiffeners on both sides) scored 92.6/100. Relative to the 8 mm solid-plate baseline, mass increased 1.4%, maximum deflection decreased 33.2%, peak stress decreased 11.3%, and cyclic retention improved 5.1%.
In this batch, design D (6 mm stiffened plate) had lower mass and 16.1% lower deflection, making it a candidate for cost-sensitive stations. Finite-element hotspot checks, material-batch tests and site service-life validation remain necessary before product design finalization.

Organization: R&D Group, Jiangsu AUREK Intelligent Technology Co., Ltd. (Lianyungang, Jiangsu) · Document type: applied industrial research · Project ARIK-RD-FIX-LW-2026-001. The full PDF includes data tables, statistical analysis and combined scoring and is available for download.

Study basis: The AUREK R&D team compared lightweight custom handling structures using project documentation and test records. Product implementation, acceptance and safety certification follow the approved design documents, test reports, approval records and applicable standards.

00Abstract

Objective: Establish a test and combined evaluation procedure for design reviews addressing the interaction between plate weight reduction, stiffness, hole-edge stress concentrations and cyclic life retention. Method: Six designs A—F varied plate thickness, longitudinal stiffeners on both sides and 12% rounded cutouts. A total of 36 prototypes underwent 1.5 kN static loading, dynamic positioning disturbances and 20,000 endurance cycles, with descriptive statistics, one-way analysis of variance, linear regression and combined scoring. Results: Design F (8 mm base plate + 12% rounded cutouts + longitudinal stiffeners on both sides) achieved mean mass 21.27 kg, maximum deflection 0.87±0.04 mm, peak equivalent stress 135.33±4.50 MPa, retention after 20,000 cycles of 96.72±0.69%, and a score of 92.6/100. Relative to design B, mass increased 1.4% and maximum deflection decreased 33.2%. Conclusion: Within these test conditions, moderate plate thickness, load-path stiffeners and controlled rounded cutouts provided favorable combined performance and warrant priority in engineering comparisons. The 6 mm stiffened design is a cost-sensitive alternative.

Keywords: custom handling tooling; lightweight design; plate thickness; stiffeners; cutouts; cyclic retention; applied research; test verification

01Introduction

Custom handling tooling provides load support, positioning, guidance and safety separation in discrete manufacturing, stamped-part transfer, automotive handling and flexible assembly. Main-plate design must assess mass, deflection, stress, weld distortion, maintenance and service-life stability together. Plate-and-shell theory explains thickness effects on bending stiffness, but engineering selection must also account for added inertia, cost and operating effort.

Stiffeners improve section efficiency by changing load paths; cutouts reduce mass by removing inefficient material. These choices also introduce weld distortion, assembly deviations and stress concentrations at hole edges, stiffener ends and weld toes. Design should therefore focus on material redistribution after defining load paths and service-life limits. Based on AUREK's main load-bearing plate project, this study compares thickness, stiffeners and rounded cutouts and provides the associated test records and evaluation methods.

02Study design and methods

2.1 Test assembly and operating conditions

The test assembly is the main load-bearing end plate of a handling fixture for plate-shaped workpieces, with an 820 mm × 300 mm × 180 mm envelope. A four-bolt interface connects it to the handling head; the working end grips and orients the workpiece. The study varies the load-bearing structure while holding suction elements, pads, coatings and pneumatic accessories constant. Test conditions are a 42 kg workpiece, 58 mm lateral center-of-gravity offset, 1.5 kN equivalent static load, 0.8 m/s² dynamic disturbance acceleration and 20,000 endurance cycles. The project-test low-alloy steel is designated M-S1, with density 7.80 × 10³ kg/m³, elastic modulus 205 GPa and nominal yield strength 355 MPa. All weld legs are 6 mm. These inputs follow the project test records; procurement and inspection follow the applicable AUREK technical documents.

2.2 Structural designs and independent variables

The test used 6 designs × 6 prototypes, totaling 36 specimens: thin plate, conventional plate, thick plate, thin stiffened plate, cutout plate and stiffened cutout plate. Consistent conditions allowed comparison of different material distributions.

Table 1 Structural designs and study objectives — data table
Design	Plate thickness/mm	Stiffeners	Cutout ratio/%	Structural features	Study objective
A	6	None	0	Lightweight solid-plate reference	Assess the thinnest plate in the comparison
B	8	None	0	Conventional solid-plate baseline	Current AUREK reference design
C	10	None	0	Conservative thick-plate design	Assess the benefit of thickness alone
D	6	Longitudinal stiffeners on both sides	0	Thin stiffened plate	Assess load-path stiffening efficiency
E	8	None	12	Central rounded cutouts	Assess the limits of cutouts alone
F	8	Longitudinal stiffeners on both sides	12	Combined cutouts and stiffeners	Assess the combined lightweight design

Table 1 Structural designs and study objectives

2.3 Test sequence and controlled variables

The test sequence comprises manufacture, static loading, dynamic checks, endurance testing and disassembly inspection. Use consistent assembly datums and welding sequences. Apply static loads of 0.50, 0.75, 1.00 and 1.25 times the design load and average 3 repetitions per specimen. Record positioning repeatability and gripping stability during dynamic testing, then measure retention after 20,000 cycles. Inspect dimensional changes at stiffener roots, cutout transitions and weld toes. Retain manufacturing records, equipment inspection/calibration records, loading photographs and cycle logs.

Table 2 Controlled variables — data table
Controlled variable	Setting	Purpose
Ambient temperature	23±2 °C	Controlled environment
Relative humidity	50%±10%	Controlled environment
Bolt tightening torque	45 N·m	Consistent installation
Weld leg size	6 mm	Consistent across all prototypes
Load-position deviation	Within ±1 mm	Reduce boundary-condition variation
Dynamic cycle rate	18 cycles/min	Consistent cycling rate
Pneumatic auxiliary pressure	0.55±0.02 MPa	Auxiliary system consistency

Table 2 Main control variables

2.4 Evaluation indicators and statistical methods

Record mass, maximum deflection, peak equivalent stress, gripping stability and retention after 20,000 cycles for each prototype. Define stiffness efficiency as effective static stiffness per unit mass:

η_K = F / (δ_mean × m_mean)（1）

Here, η_K is the stiffness efficiency, F is the static load test load, δ_mean is the group mean maximum deflection, m_mean is the group mean mass. A 100-point combined score balances performance and implementation cost:

S = 100 × (0.30·K_norm + 0.25·σ_rev + 0.20·L_norm + 0.15·P_norm + 0.10·C_rev)（2）

Here, K_norm is the normalized stiffness-efficiency score, σ_rev is the reverse-normalized peak-stress score, L_norm is the normalized cyclic-retention score, P_norm is the normalized gripping-stability score, and C_rev is the reverse-normalized cost score. Each input is normalized to 0–1. Descriptive statistics, one-way analysis of variance and linear regression compare this prototype batch under the stated conditions, using a significance threshold of P<0.05. Product certification follows the formal verification and approval process.

03Results

3.1 Descriptive statistics and combined ranking

In this batch, design A had the lowest mass but weaker deflection and life performance. Design C substantially improved stiffness at the highest mass and cost. Design D demonstrated the stiffness efficiency of stiffeners along the main load path, while design E showed that cutouts alone may reduce stability. Design F provided a balanced combination of stiffness efficiency, stress, stability and cyclic retention.

Table 3 Results for six designs — data table
Design	Mass/kg	Maximum deflection/mm	Peak stress/MPa	Gripping stability/%	Cyclic retention/%	Stiffness efficiency	Estimated cost / RMB 10,000	Combined score
A: 6 mm solid plate	18.43±0.13	1.91±0.06	183.67±1.21	92.88±0.62	88.15±0.48	42.74	1.50	10.0
B: 8 mm solid plate	20.98±0.16	1.29±0.06	152.50±4.55	94.98±0.42	92.07±0.77	55.20	1.66	47.8
C: 10 mm solid plate	24.14±0.14	0.94±0.04	140.17±4.31	95.97±0.49	93.52±0.82	65.87	1.84	64.0
D: 6 mm stiffened plate	19.18±0.19	1.09±0.05	145.67±2.42	95.82±0.59	94.50±0.25	71.97	1.68	72.3
E: 8 mm plate with cutouts	20.32±0.23	1.39±0.06	158.33±4.76	94.45±0.39	90.87±0.46	53.30	1.63	39.4
F: 8 mm plate with cutouts and stiffeners	21.27±0.14	0.87±0.04	135.33±4.50	97.05±0.30	96.72±0.69	81.54	1.75	92.6

Table 3 Results for six designs (mean ± standard deviation, n=6)

A: 6 mm solid plate1.91 mm

B: 8 mm solid plate1.29 mm

C: 10 mm solid plate0.94 mm

D: 6 mm stiffened plate1.09 mm

E: 8 mm plate with cutouts1.39 mm

F: 8 mm plate with cutouts and stiffeners0.87 mm

Figure 1 Mean maximum deflection for six designs; lower values are better, with design F lowest.

A: 6 mm solid plate10.0

B: 8 mm solid plate47.8

C: 10 mm solid plate64.0

D: 6 mm stiffened plate72.3

E: 8 mm plate with cutouts39.4

F: 8 mm plate with cutouts and stiffeners92.6

Figure 2 Combined scores for six designs on a 100-point scale; design F scores 92.6.

3.2 Between-group differences and regression analysis

One-way analysis of variance found significant differences between the six designs in maximum deflection, peak equivalent stress and retention after 20,000 cycles. This supports distinguishing performance within this prototype batch and test conditions; selection still requires subsequent engineering validation.

Table 4 One-way ANOVA — data table
Measure	F value	P value	Significance
Maximum deflection/mm	336.34	2.17e-25	P<0.001
Peak equivalent stress/MPa	120.53	6.34e-19	P<0.001
Retention after 20,000 cycles/%	142.49	5.81e-20	P<0.001

Table 4 One-way ANOVA: between-group degrees of freedom 5, within-group degrees of freedom 30

Fit maximum deflection as the dependent variable using plate thickness T, stiffener presence R and cutout ratio H as predictors:

δ_max = 3.149 − 0.224·T − 0.653·R + 0.0077·H　(Adjusted R² = 0.939)（3）

Within this sample, both increased thickness and stiffeners corresponded to reduced deflection, with a greater marginal effect from stiffeners. Increased cutout ratio corresponded to a slight deflection increase. Cutout placement should therefore be assessed together with load-path reinforcement.

Table 5 Maximum-deflection regression — data table
Variable	Coefficient	Standard error	t value	P value
Intercept	3.1491	0.0940	33.49	P<0.001
Plate thickness T/mm	−0.2238	0.0118	−18.98	P<0.001
Stiffeners R (0/1)	−0.6532	0.0350	−18.67	P<0.001
Cutout ratio H/%	0.0077	0.0028	2.78	0.009

Table 5 Maximum-deflection regression: R is a 0/1 indicator; adjusted R²=0.939

3.3 Changes relative to the baseline

Relative to the company's current design B (8 mm solid plate), design F in this batch increased mass by approximately 1.4%, reduced maximum deflection by 33.2% and peak stress by 11.3%, and improved cyclic retention by 5.1%. Design D reduced mass by 8.6% and maximum deflection by 16.1%. The former warrants priority in overall-performance comparisons and the latter in cost-sensitive station comparisons.

Table 6 Changes relative to design B — data table
Design	Mass change	Maximum-deflection change	Peak-stress change	Cyclic-retention change	Combined score
A: 6 mm solid plate	−12.2%	+47.1%	+20.4%	−4.3%	10.0
C: 10 mm solid plate	+15.0%	−27.2%	−8.1%	+1.6%	64.0
D: 6 mm stiffened plate	−8.6%	−16.1%	−4.5%	+2.6%	72.3
E: 8 mm plate with cutouts	−3.2%	+6.9%	+3.8%	−1.3%	39.4
F: 8 mm plate with cutouts and stiffeners	+1.4%	−33.2%	−11.3%	+5.1%	92.6

Table 6 Changes relative to design B; negative deflection/stress changes indicate improvement

A: 6 mm solid plate88.15%

B: 8 mm solid plate92.07%

C: 10 mm solid plate93.52%

D: 6 mm stiffened plate94.50%

E: 8 mm plate with cutouts90.87%

F: 8 mm plate with cutouts and stiffeners96.72%

Figure 3 — Retention-rate comparison for six designs after 20,000 cycles (Design F: 96.72%)

04Discussion

4.1 Explanation of structural efficiency

The results show that material placement affects lightweighting performance. Thickening increases static stiffness but does not necessarily use material efficiently. Longitudinal stiffeners on both sides place material where it supports bending resistance, improving thin-plate stiffness efficiency. Design F preserves the main load path and bending section with longitudinal stiffeners while using 12% rounded cutouts to remove inefficient material. Design E shows that cutouts without corresponding load-path adjustments can weaken the structure. Cutout ratio, corner radii, hole-edge-to-weld-toe distance, stiffener-end transitions and burr control must be checked together.

4.2 Application criteria

Design F is a candidate where overall performance takes priority, for assessing higher-cycle-rate stations with tighter positioning requirements. Design D is a cost-sensitive alternative for stations with strong initial-unit cost constraints that also need improved operating feel and cyclic retention. Design C can be assessed where weight is less critical and conservative redundancy is required, but is not a routine lightweighting approach.

Table 7 Implementation risk matrix — data table
Risk category	Specific risk	Probability	Impact	Risk level	Controls
Structural	Stress hotspots at cutout edges or stiffener ends	Medium	High	High	Specify consistent corner radii and transition chamfers; verify hotspot regions
Manufacturing	Weld distortion exceeds available straightening capability	Medium	Medium	Medium	Specify welding sequence, distortion-control fixtures and post-weld measurements
Measurement quality	Displacement/strain measurement drift changes design rankings	Low	High	Medium	Calibrate before and after testing; repeat key specimen measurements
Operation	Use outside the design operating conditions	Medium	High	High	State permitted operating conditions in drawings, SOPs and training
Decision-making	Treating interim test results as product certification	Medium	High	High	Identify the verification stage and scope in drawings, reports, conclusions and approvals

Table 7 Implementation risk matrix

4.3 Limitations

The conclusions apply to this prototype batch and the stated conditions; statistical significance compares relative trends. Engineering-equivalent parameters were used for material properties, weld heat-affected zones and residual stress, so batch variability still requires review. Endurance validation covered 20,000 cycles; longer service lives require further verification. Before finalizing the product, complete finite-element hotspot checks, material-batch tests, weld-distortion compensation, station-level ergonomic assessment, small-batch site trials and the formal certification process.

05Implementation plan

Proceed through requirements freeze, design, prototype manufacture, experimental validation, site trials and design finalization, retaining deliverables at each stage. Before finalization, cross-check the five record groups: drawings/BOM/SOP, prototype manufacture, raw test records, photos/videos, and review approvals. Do not proceed directly to site use while documentation or validation is incomplete.

Table 8 Implementation phases and deliverables — data table
Stage	Schedule	Main task	Deliverables	Responsible department
Requirements definition	Weeks 1-2	Define operating conditions, performance measures and budget	Project brief and design-input register	Project office and structural engineering team
Concept design	Weeks 3-6	Complete and review the design	Drawings, review minutes	Structural engineering team and simulation team
Prototype manufacturing	Weeks 7-11	Cutting, welding, assembly and straightening	36 prototypes and manufacturing records	Manufacturing engineering team
Test verification	Weeks 12-16	Static, dynamic, endurance and follow-up inspections	Test reports, raw data	Test team
Site trial	Weeks 17-20	Limited production rollout and issue capture	Trial logs and corrective-action records	Project office and manufacturing representatives
Design finalization	Weeks 21-24	Complete documentation for standard and cost-focused versions	Approved BOM, SOPs and training materials	All participating teams

Table 8 Proposed implementation phases and deliverables

Table 9 Project budget estimate — data table
Budget category	Amount / RMB 10,000	Proportion	Description
Design and simulation	24	13.7%	Drawings, parameter analysis, data processing
Prototype materials and manufacture	52	29.7%	Raw materials, welding, assembly and rework for 36 prototypes
Test verification	46	26.3%	Test-rig use, metrology, endurance testing and retests
Site trials and training	21	12.0%	Trial operation support, operation guidance and training
Quality, compliance and EHS	12	6.9%	Review, audit, safety control
Contingency	20	11.4%	Additional prototypes, supply variation and corrective work
Total	175	100%	24-week total project budget

Table 9 Project budget estimate

Prototype materials and manufactureRMB 520,000 · 29.7%

Test verificationRMB 460,000 · 26.3%

Design and simulationRMB 240,000 · 13.7%

Site trials and trainingRMB 210,000 · 12.0%

ContingencyRMB 200,000 · 11.4%

Quality, compliance and EHSRMB 120,000 · 6.9%

Figure 4 Project budget: RMB 1.75 million over 24 weeks

06Conclusions

(1) Under these test conditions, design F (8 mm base plate + 12% rounded cutouts + longitudinal stiffeners on both sides) achieved the highest combined score and warrants priority in upgrade comparisons. (2) Design D (6 mm stiffened plate) had lower mass and deflection than design B and is a cost-sensitive alternative. (3) Thickening alone incurs higher mass and cost; cutouts alone may increase deflection and life variability. (4) Lightweight design should prioritize material along principal load paths and efficient section locations. (5) Material, welding, finite-element hotspot, site service-life and safety-risk validation must be completed before project introduction and product finalization, with formal validation and certification records.

07References

[1] TIMOSHENKO S P, WOINOWSKY-KRIEGER S. Theory of Plates and Shells[M]. 2nd ed. New York: McGraw-Hill, 1959.
[2] PILKEY W D, PILKEY D F. Peterson's Stress Concentration Factors[M]. 3rd ed. Hoboken: John Wiley & Sons, 2008.
[3] MONTGOMERY D C. Design and Analysis of Experiments[M]. 10th ed. Hoboken: John Wiley & Sons, 2019.
[4] DIETER G E, SCHMIDT L C. Engineering Design[M]. 5th ed. New York: McGraw-Hill Education, 2013.
[5] ISO 12100:2010. Safety of machinery — General principles for design — Risk assessment and risk reduction[S].
[6] GB/T 7714-2015. Information and documentation — Rules for bibliographic references and citations to information resources[S].

08Data availability and application scope

Data availability: The data come from AUREK R&D project test records. Appendices A and B of the PDF provide raw data for 36 prototypes and scoring weights. Access to proprietary source records, drawings and approvals may be requested from AUREK R&D management within the permitted scope.
Application: Project implementation uses its own approved design, test, approval and acceptance documents.
Appendices: Appendix A contains the 36-prototype dataset; Appendix B gives scoring weights and the recalculation method.

Need to reduce tooling weight? Share the workpiece weight, station cycle time, positioning accuracy and cost target. AUREK can use this framework to assess structural designs and the required verification tests.

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