- The essence of lightweight fixtures is not "material reduction";Material redistribution under well-defined load paths and life boundaries——It is not advisable to blindly thicken or blindly hollow out.
- Assume six types of structural schemes A to F, 36 prototypes, and perform 1.5 kN static load, dynamic disturbance and Durability over 20,000 cyclesExperiment and make decisions using analysis of variance, linear regression, and a 100-point composite score.
- Plan F(8 mm base plate + 12% rounded corner hollowing + bilateral longitudinal ribs) comprehensive score 92.6/100; compared with the 8 mm solid plate benchmark, the quality only increased by 1.4%,Maximum deflection reduced by 33.2%, the peak stress dropped by 11.3%, and the cycle retention rate increased by 5.1%.
- Plan D(6 mm reinforcement) has lower mass and 16.1% reduction in deflection, making it a cost-sensitive alternative; product finalization still requires supplementary finite element hot spots, material batches, and on-site life verification.
Organization: Jiangsu Aurek Intelligent Technology Co., Ltd. R&D Team (Lianyungang, Jiangsu) · Resource type: Enterprise Application Research · Project No. ARIK-RD-FIX-LW-2026-001 · Includes complete data tables, statistical analysis, and composite scoring. The full PDF can be downloaded at the end of the page or from the upper-right link.
00Abstract
Purpose:In view of the coupling contradiction between weight reduction, stiffness, hole edge stress concentration and cycle life maintenance of the main load-bearing plate of the custom handling tooling, a test verification and comprehensive evaluation process suitable for enterprise plan review was established.Method:Set up six types of structural schemes from A to F, and prepare 36 test prototypes around three types of variables: plate thickness, bilateral longitudinal stiffeners, and 12% fillet hollows. They completed 1.5 kN static load, dynamic positioning disturbance, and 20,000 cycle durability evaluations, and used descriptive statistics, single-factor analysis of variance, linear regression, and comprehensive scoring models for comparison.Result:Plan F (8 mm base plate + 12% fillet hollow + bilateral longitudinal reinforcement) has an average mass of 21.27 kg, a maximum deflection of 0.87±0.04 mm, a peak equivalent stress of 135.33±4.50 MPa, a retention rate of 96.72±0.69% for 20,000 cycles, and a comprehensive score of 92.6/100; based on B Plan F is the baseline, and Plan F reduces the maximum deflection by 33.2% with only a 1.4% increase in mass.Conclusion:Within the research boundaries of this article, "medium plate thickness + stress path stiffeners + controlled fillet hollowing" is better than simple thickening or simple material reduction, and can be used as a priority introduction route for enterprises; the 6 mm reinforcement solution can be used as a cost-sensitive alternative.
01Introduction
In discrete manufacturing, stamping parts turnover, automotive parts handling and flexible assembly stations, custom handling tooling usually have the functions of carrying, positioning, guiding and safety isolation. For plate tooling units, the difficulty in engineering design is not a single load-bearing check, but how to obtain an importable comprehensive balance between quality, deflection, stress, welding deformation, maintenance convenience and life stability. Classic plate and shell theory shows that changes in plate thickness have a strong impact on bending stiffness; however, in enterprise productization scenarios, simply increasing plate thickness often leads to an increase in inertia, cost, and operating burden.
Reinforcing ribs and hollowing are the two most common methods used in lightweight design by enterprises: the former improves cross-sectional efficiency by reconstructing the force path, and the latter reduces structural quality by removing inefficient materials. However, hollowing out will introduce local stress concentration near the edge of the hole, the termination end of the rib plate and the weld toe; the rib may also amplify the welding deformation and assembly deviation. Therefore, fixture lightweighting should not be understood as simple material reduction, but should be defined asMaterial redistribution under well-defined load paths and life boundaries. This article relies on the custom handling tooling lightweight enterprise project of the AUREK R&D team to conduct real enterprise application research on the plate thickness, stiffeners and rounded corner hollows of the main load-bearing plate, forming a reviewable data link and design evaluation logic.
02Research objects and methods
2.1 Research objects and boundary conditions
The research object is the main load-bearing end plate assembly of a type of plate-shaped workpiece handling fixture. The test envelope size is 820 mm × 300 mm × 180 mm. The installation end is connected to the handling head through a four-point bolt interface, and the working end is responsible for workpiece clamping and orientation constraints. In order to reduce variable interference, only the load-bearing structure body is examined, and suction components, cushions, coatings and pneumatic accessories are not considered as independent variables. Unified working conditions: workpiece mass 42 kg, lateral center of gravity offset 58 mm, equivalent static load 1.5 kN, dynamic disturbance acceleration 0.8 m/s², cycle durability 20,000 times. The material is low-alloy structural steel for project testing (internal code M-S1, density 7.80 × 10³ kg/m³, elastic modulus 205 GPa, nominal yield 355 MPa), and the welding feet are uniformly 6 mm; the above values are organized according to internal test records, and formal procurement and inspection are subject to the company's technical documents.
2.2 Structural scheme and independent variables
An experimental design of 6 plans × 6 prototypes was adopted, with a total of 36 prototypes covering six typical engineering ideas of "light plate, conventional plate, thick plate, thin plate reinforcement, hollow plate, and hollow reinforcement".
| solution | Plate thickness/mm | Reinforcement ribs | Hollow rate/% | Structural features | research objective |
|---|---|---|---|---|---|
| A | 6 | None | 0 | Solid lightweighting reference plate | Observe extreme thinning performance |
| B | 8 | None | 0 | Conventional benchmark real board | as the company's current benchmark |
| C | 10 | None | 0 | Thick plate conservative plan | Verification of simply increasing income |
| D | 6 | Bilateral longitudinal ribs | 0 | Thin plate reinforcement | Verify the reinforcement efficiency of the stress path |
| E | 8 | None | 12 | Middle rounded corner cutout | Verify simple hollow boundary |
| F | 8 | Bilateral longitudinal ribs | 12 | Hollow reinforcement synergy | Verify the effect of collaborative lightweighting |
Table 1 Structural plan and research intention
2.3 Test process and control variables
The test verification process includes five stages: prototype manufacturing, static load verification, dynamic verification, durability test and disassembly review: the manufacturing stage unifies the assembly benchmark and welding sequence; the static load is loaded in stages according to 0.50, 0.75, 1.00, and 1.25 times the design load, and each piece is repeated 3 times to take the average; the dynamic stage records repeated positioning deviations and clamping stability; the durability stage is based on 20,000 The retention rate is recorded in each cycle; the final inspection reviews the geometric deviation of the rib root, hole edge transition area and weld toe area. The process is synchronized to form manufacturing records, equipment inspection/calibration records, loading photos and cycle records.
| Controls | set value | purpose |
|---|---|---|
| ambient temperature | 23±2 °C | controlled environment |
| Relative Humidity | 50%±10% | controlled environment |
| Bolt pretightening torque | 45 N·m | Install consistency control |
| Welding leg size | 6 mm | Consistent across all prototypes |
| Loading position deviation | Within ±1 mm | Reduce boundary error |
| dynamic beat | 18 cycles/min | unified cycle rhythm |
| Pneumatic auxiliary pressure | 0.55±0.02 MPa | Auxiliary system consistency |
Table 2 Main control variables
2.4 Evaluation indicators and statistical methods
Each prototype records five core indicators: quality, maximum deflection, peak equivalent stress, clamping stability and 20,000 cycle retention rate. Stiffness efficiency is defined as the effective static stiffness corresponding to unit mass:
where ηK is the stiffness efficiency, F is the static load test load, δmean is the average maximum deflection of the same group, mmean is the average quality of the same group. In order to balance performance and import economy, a 100-point comprehensive score is constructed:
where Knorm is the stiffness efficiency normalized score, σrev is the reverse normalized score of peak stress, Lnorm is the normalized score for cycle retention rate, Pnorm Normalized score for clamping stability, Crev Inverse normalized score for cost. Statistical processing includes descriptive statistics, one-factor analysis of variance and linear regression. The significance threshold is P<0.05, which is used to evaluate the program differences of this batch of prototypes under set working conditions; product certification is still subject to the company's formal verification and approval documents.
03Result
3.1 Descriptive statistics and comprehensive ranking
Plan A has the lowest quality but weak deflection and life; Plan C has obvious improvement in stiffness but the highest quality and cost; Plan D shows that laying reinforcement along the main stress path can improve the stiffness efficiency at lower mass; Plan E suggests that simple hollowing may weaken stability; Plan F has comprehensive advantages in stiffness efficiency, stress level, stability and life maintenance.
| solution | Mass/kg | Maximum deflection/mm | Peak stress/MPa | Clamping stability/% | Cycle retention rate/% | stiffness efficiency | Estimated cost/RMB ten-thousands | Overall rating |
|---|---|---|---|---|---|---|---|---|
| A 6 mm solid board | 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 board | 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 board | 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 reinforced | 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 hollow | 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 hollow + reinforced | 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 Summary of main indicators of the six groups of plans (mean ± standard deviation, n=6)
3.2 Differences and regression analysis between groups
One-factor analysis of variance showed that there were significant differences in the maximum deflection, peak equivalent stress, and 20,000-cycle retention rate among the six groups of solutions, indicating that the differences in the solutions had clear structural design effects rather than random disturbances.
| Evaluation index | F value | P value | judge |
|---|---|---|---|
| Maximum deflection/mm | 336.34 | 2.17e-25 | P<0.001 |
| Peak equivalent stress/MPa | 120.53 | 6.34e-19 | P<0.001 |
| 20,000 cycles retention rate/% | 142.49 | 5.81e-20 | P<0.001 |
Table 4: Single-factor analysis of variance results for key indicators (degrees of freedom between groups 5, within groups 30)
Establish a linear regression with the maximum deflection as the dependent variable, plate thickness T, whether to reinforce or not R, and hollowing rate H as the independent variables:
Increasing plate thickness and setting up reinforcing ribs can reduce deflection, among which the marginal impact of reinforcing ribs is more significant in this batch of samples; increasing the hollowing rate will slightly increase the deflection, which must be coordinated with the strengthening design of the stress path.
| 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 |
| Reinforcement R(0/1) | −0.6532 | 0.0350 | −18.67 | P<0.001 |
| Hollow rate H/% | 0.0077 | 0.0028 | 2.78 | 0.009 |
Table 5 Maximum deflection linear regression results (R is 0/1 dummy variable, model adjustment R²=0.939)
3.3 Improvement compared to the baseline solution
Taking Plan B (8 mm solid plate) as the company's current benchmark: Plan F reduces the maximum deflection by 33.2%, reduces the peak stress by 11.3%, and increases the cycle retention rate by 5.1%, while reducing the quality by only about 1.4%; Plan D reduces the maximum deflection by 16.1% while reducing the quality by 8.6%, making it more suitable as a cost-sensitive workstation alternative.
| solution | mass change | maximum deflection change | peak stress change | Cycle retention rate changes | Overall rating |
|---|---|---|---|---|---|
| A 6 mm solid board | −12.2% | +47.1% | +20.4% | −4.3% | 10.0 |
| C 10 mm solid board | +15.0% | −27.2% | −8.1% | +1.6% | 64.0 |
| D 6 mm reinforced | −8.6% | −16.1% | −4.5% | +2.6% | 72.3 |
| E 8 mm hollow | −3.2% | +6.9% | +3.8% | −1.3% | 39.4 |
| F 8 mm hollow + reinforced | +1.4% | −33.2% | −11.3% | +5.1% | 92.6 |
Table 6: Changes in main indicators compared to option B (negative deflection/stress is favorable)
04discuss
4.1 Explanation of structural efficiency
The results of this article support the lightweight logic of "load path priority": simple thickening can improve static stiffness, but the distribution of material input may not be the most effective; double-sided longitudinal stiffeners place materials in positions that are more sensitive to cross-section bending, so that thin plate solutions can also achieve higher stiffness efficiency. The advantage of Plan F comes from two synergies - the longitudinal reinforcement retains the main stress path and bending section, and the 12% fillet hollowing removes material in inefficient areas without cutting off key stress channels. Plan E shows that if the hollowing is separated from the stress path reconstruction, it is easy to mistake lightweighting for a simple weakened structure; the hollowing proportion, hole corner radius, distance from hole edge to welding toe, stiffener end transition and processing burr control should be used as joint constraints.
4.2 Engineering application boundaries
Plan F is recommended asStandard upgraded version(Applicable to workstations with higher cycle time, stricter positioning requirements, and hoping to form an internal technical model). Plan D is used ascost sensitive version(Scenarios with stronger first-piece cost constraints but still hoping to improve control and longevity); Plan C can be used as a special case that is not weight-sensitive and requires conservative redundancy, and is not suitable for conventional lightweight routes.
| risk category | specific risks | Probability | influence | level | control measures |
|---|---|---|---|---|---|
| structural risk | Stress hot spots are formed at the edge of the hole or at the termination end of the rib plate | in | high | high | Unify the hole corner radius, set transition chamfer and review the hot spot area |
| process risk | The welding deformation after reinforcement exceeds the correction capability | in | in | in | Formulate welding sequence, anti-deformation tooling and post-weld retesting |
| quality risk | Displacement or strain measurement drift affects sequencing | Low | high | in | Calibration before and after the test, repeated measurements of key samples |
| operational risk | On-site misuse exceeding design conditions | in | high | high | Solidify working condition boundaries in drawings, SOPs and training |
| decision risk | Mistaking phased test results as product certification conclusions | in | high | high | Clarify verification phases and boundaries in drawings, reports, conclusions and approvals |
Table 7 Enterprise introduction risk matrix
4.3 Limitations
This article has four main limitations: first, the data comes from this batch of prototype testing and statistical compilation, which still needs to be confirmed through the formal certification process; second, the material properties, welding heat-affected zone and residual stress adopt engineering equivalent parameters, which need to be continuously reviewed in conjunction with batch discreteness; third, the durability verification only covers 20,000 cycles and needs to be extended to a longer life range; fourth, the statistical significance is based on this batch of samples to illustrate the relative trend between structural solutions. Before product finalization, finite element hot spot review, material batch testing, welding deformation compensation, station-level ergonomic evaluation and on-site small batch trial operation should be supplemented.
05Enterprise implementation suggestions
It is recommended to adopt stage gate management: demand freezing, scheme design, prototype manufacturing, experimental verification, on-site trial operation and design finalization. Auditable deliverables are formed at each stage to avoid entering the site in a state of "with plan, no evidence" or "with test, no documents". Before finalizing the design, complete the five-category evidence chain closed loop of "drawings/BOM/SOP—prototype manufacturing—original test records—photos/videos—review and approval".
| Stage | cycle | core mission | main deliverables | Responsible department |
|---|---|---|---|---|
| demand freeze | Weeks 1-2 | Clarify work conditions, indicators and budget boundaries | Mission statement, input boundary table | Project Office, Structure Team |
| Scheme design | Weeks 3-6 | Complete program design and review | Drawings, review minutes | Structural engineering team and simulation team |
| Prototype manufacturing | Weeks 7-11 | Cutting, welding, assembly and calibration | 36 pieces of prototypes and process records | Technology group |
| Experimental verification | Weeks 12-16 | Static load, dynamic, durability and re-inspection | Test reports, raw data | experimental group |
| On-site trial operation | Weeks 17-20 | Limited production rollout and issue capture | Trial operation log, rectification order | Project office, manufacturing interface |
| Design finalization | Weeks 21-24 | Form standard version and cost version documents | Finalized BOM, SOP, training parts | All collaboration |
Table 8: Recommended implementation phases and deliverables
| Budget module | Amount/RMB ten-thousands | Proportion | Description |
|---|---|---|---|
| Design and Simulation | 24 | 13.7% | Drawings, parameter analysis, data processing |
| Prototype materials and processing | 52 | 29.7% | 36 pieces of prototype raw materials, welding, assembly and rework |
| Experimental verification | 46 | 26.3% | Bench occupancy, measurement, durability and retesting |
| On-site trial operation and training | 21 | 12.0% | Trial operation support, operation guidance and training |
| Quality Compliance and EHS | 12 | 6.9% | Review, audit, safety control |
| reserve fund | 20 | 11.4% | Second trial production, supply fluctuations, abnormal rectification |
| total | 175 | 100% | 24-week total project budget |
Table 9 Project budget estimate
06Conclusion
(1) Under the test conditions of this article, Plan F (8 mm base plate + 12% rounded corner hollows + bilateral longitudinal reinforcements) has the highest overall score and can be used as a priority introduction route for the enterprise standard upgrade version; (2) Plan D (6 mm reinforcement) has lower quality than Plan B while significantly reducing deflection, and can be used as an alternative for cost-sensitive scenarios; (3) Simply thickening improves static stiffness but comes at a higher cost in quality and cost. Although pure hollowing can reduce weight, it may amplify deflection and life span fluctuations; (4) The key to lightweight fixtures is not the amount of material removal, but the reconfiguration of the material in the main stress path and efficient cross-section position; (5) Materials, welding, finite element hotspots, on-site life and safety risk verification must be supplemented before project introduction and product finalization, and formal verification and certification documents are the final basis.
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 literature reference description rules[S].
08Statements and Data Availability
Data availability:The test data come from AUREK R&D project test records. Raw data and scoring weights for 36 prototypes are provided in Appendices A and B of the full PDF. Because the source material includes proprietary technical information, original records, drawings, and approval documents may be requested from the company's R&D management team where reasonably appropriate.
Research boundaries:This enterprise application research does not replace the formal design, test, approval, or acceptance documentation for a specific project.
Appendix:The full PDF includes Appendix A (raw data for 36 prototypes) and Appendix B (composite-scoring weights and recalculation method).