Strength Optimization of Infant Pop-Up Seat Frame Using Discrete Material and Thickness Optimization

In this paper, the authors proposed an optimal design method for the strength design of infant pop-up seat frame combined with rear seats for infants, children, and adults, not removable booster seats or car seats. Frame strength design was performed using discrete material and thickness optimization (DMTO) method considering high strength steel (HSS) and advanced high strength steel (AHSS). Structural design using the Section 4 link mechanism was performed, and the weakness of the seat frame due to static load was confirmed through finite element analysis. An optimal design criterion was established by carrying out a case study to derive the limiting conditions according to static and dynamic loads. In consideration of these criteria, the optimal design according to d-optimal and discrete Latin-hypercube (DLH) was performed among the design of experiments (DOE). And the strength of the pop-up seat frame for infants according to each DOE was checked, and the strength optimization method was suggested by comparing the lightweight ratio.

Optimum structural design of seat frames for commercial vehicles

Seat frames in commercial vehicles generally consist of components such as foot brackets, seats, back, head restraints and fasteners. In addition to mechanical properties, comfort is another important parameter. This study aims to reduce the cost of a commercial vehicle by means of alternative materials and design changes in the passenger seat frame. For this purpose, three different methods were used to optimize seat back pipes: reducing the cross-section, using thinner sections in the seat frame via alternative material and making design changes in the foot brackets. In the methods applied, mitigation and cost reductions were achieved. The suitability of the design changes in the seat through geometric changes was confirmed by international ECE R14 test results and finite element method analyses.

Enhanced Robust Design Optimization in Seat Belt Anchorage Strength for Front Crash Safety of Multi-Purpose Vehicle

This paper deals with an enhanced robust design optimization (RDO) method and its application to the strength design problem of seat belt anchorage, related to the front crash safety of multi-purpose vehicles. In order to determine the rational design safety of the newly developed automotive part, such as the seat, in which the reliability of the evaluation data is not sufficient at the design stage, it is necessary to implement a probabilistic design considering uncertainties. Thickness size variables of the seat frame structure’s members were considered random design variables, including uncertainties such as manufacturing tolerance, which are an inevitable hazard in the design of automotive parts. Probabilistic constraints were selected from the strength performances of the seat belt anchorage test, which are regulated in Economic Commission for Europe (ECE) and Federal Motor Vehicle Safety Standard (FMVSS), and the strength performances were evaluated by finite element analyses. The RDO problem was formulated such that the random design variables were determined by minimizing the seat frame weight subject to the probabilistic strength performance constraints evaluated from the reliability analyses. Three sigma level quality was considered for robustness in side constraints. The mean value reliability method (MVRM) and adaptive importance sampling method (AISM) were used for the reliability analyses in the RDO, and reliability probabilities from the MVRM and the AISM on the probabilistic optimum design were assessed by Monte Carlo simulation (MCS). The RDO results according to the reliability analysis methods were compared to determine the optimum design results. In the case of the RDO with the AISM, the structure reliability was fully satisfied for all the constraint functions, so the most reliable structural safety was guaranteed for the seat frame design.

Optimization of Seat Frame With Dissimilar Materials for Lightweight Materials

High-strength and lightweight methods for vehicle parts include methods such as optimization and application of lightweight materials by reflecting load or material characteristics. Safety regulations have been established in accordance with the loads affecting the vehicle to secure the safety of the vehicle. In order to reduce the weight, high strength materials such as high strength steel (HSS) or high tensile strength steel (AHSS) have been studied. In addition, research on additional lightweight optimization is actively performed by removing parts that do not require high strength or replacing them with plastics. The process of designing a vehicle or part with different properties and considering various loads is costly and time consuming. In order to secure safety and light weight, the authors propose an approximate model for the optimal design of the seat frame that has a direct impact on occupants among the parts of the vehicle, and reduces the development cost, time, and intuitive design through the procedure.

Using the COVID-19 Economic Crisis to Frame Climate Change as a Secondary Issue Reduces Mitigation Support

The COVID-19 pandemic has understandably dominated public discourse,crowding out other important issues such as climate change. Currently, if climate change enters the arena of public debate, it primarily does so in direct relation to the pandemic. In two experiments, we investigated (1) whether portraying the response to the COVID-19 threat as a “trial run” for future climate action would increase climate-change concern and mitigation support, and (2) whether portraying climate change as a concern that needs to take a “back seat” while focus lies on economic recovery would decrease climate-change concern and mitigation support. We found no support for the effectiveness of a trial-run frame in either experiment. In Experiment 1, we found that a back-seat frame reduced participants’ support for mitigative action. In Experiment 2, the back-seat framing reduced both climate-change concern and mitigation support; a combined inoculation and refutation was able to offset the drop in climate concern but not the reduction in mitigation support.