Structure Design Research Articles

Revolutionizing tire engineering: Finite element analysis and design of an X-shaped spoke structure for non-pneumatic military tires

In this study, we developed a non-pneumatic tire (NPT) specifically designed for military vehicles, such as the Humvee. Our aim was to enhance performance on challenging terrains crucial for mission success. We selected a novel X-shaped polygonal structure for the spoke design owing its exceptional load-carrying capacity and durability. The equivalent modulus, which is the key factor in spoke design, was analytically derived and formulated. This calculated modulus served as a benchmark for achieving the desired vertical stiffness of the NPT. We manufactured a prototype NPT and evaluated its mechanical properties by using a polyurethane (PU) spoke structure. Multiple finite element models of the novel NPT, considering different parameters such as the number of spoke sections, thickness, and modulus of elasticity, were developed while maintaining a consistent equivalent modulus value. Dynamic finite element analysis was then performed to assess the rolling performance of the NPT. We found that the maximum dynamic stress at the spoke was 2.387 MPa, which is 0.398 times the allowable yield strength of the PU spoke. This finding confirms the durability of the novel NPT under dynamic usage in military vehicles, with promising implications for overcoming challenging terrains.

Chiral twisted molecular carbons: Synthesis, properties, and applications

AbstractIn recent years, the precisely controlled synthesis of chiral twisted molecular carbons has emerged as a forefront topic in the research of carbon materials. Molecular carbons refer to carbon nanomaterials synthesized with precision at the atomic level. Through rational design, rigid and stable chiral twisted structures can be synthesized. The exploration in the field of chiral twisted molecular carbons is key to fully understanding the various twisted configurations of carbon materials and delving into the relationship between structure design and functionality. This review explores chiral twisted configurations of carbon nanomaterials such as nanographene, carbon nanobelts, carbon nanosheets, graphdiyne, etc. It emphasizes the role of photocyclization, Scholl reaction, and Diels–Alder reactions in achieving precise chiral control and discusses a range of innovative design strategies. These strategies have led to the development of various twisted structures, such as helical, propeller, and Möbius strip configurations. The introduction of chirality, combined with the inherent exceptional optical properties of nanocarbon materials, has facilitated the creation of materials with superior chiroptical performances. This advancement is driving applications in fields such as optoelectronics and chiral optics.

Design, Perspective, and Challenge of Niobium‐Based Anode Materials for High‐Energy Alkali Metal‐Ion Batteries

AbstractThe rapid advancement of clean energy has aroused an increased demand for advanced energy storage systems. Alkali metal‐ion batteries (AMIBs) including lithium/sodium/potassium‐ion batteries (LIBs/SIBs/PIBs) play a crucial role in these systems, and their development is closely related to the progress of electrode materials. Niobium (Nb)‐based materials exhibit distinctive features such as quasi‐2D framework, high intercalation potential, robust pseudo‐capacitance effect, and minimal volume expansion during cycles. These characteristics render them highly valuable for energy storage applications. However, the low conductivity and limited capacity of Nb‐based electrode materials significantly limit their widespread development in energy storage applications. To address these challenges, various strategies have been explored. This review primarily summarizes the recent advancements in research on Nb‐based anode materials for AMIBs over the past decade. The synthesis strategy, structure design, and material composite of Nb‐based materials are systematically discussed, and the performances of different types of batteries are also well analyzed and compared. Meanwhile, their merits in the fast‐charging realm are then highlighted. Importantly, this review presents the key issues and challenges encountered by Nb‐based anode materials in future energy storage, along with novel concepts and solutions for the research and development of next‐generation Nb‐based anodes.

Neural networks-based spring element for second-order analysis of pile-supported structures with nonlinear soil- structure interaction

This paper proposes a novel structural analysis approach, the neural networks-based spring element (NNSE) method, to synergize machine learning (ML) techniques with the line finite element method (LFEM) for the second-order analysis method of pile-supported structures. Traditional LFEM, widely used in upper structure design, showcases limitations in efficiently modeling complex Soil-Structure Interaction (SSI) along piles since it requires dense element mesh for accuracy. Conversely, ML offers a mesh-free alternative for analyzing single piles but struggles in simulating pile-supported structures as the training sample collection for large-scale problems might be unbearable. This paper addresses these challenges by proposing a new analysis framework to utilize the neural network (NN) model, which only describes structural responses of single piles, for the simulation of entire pile-supported structures. In the proposed method, the NN model is not directly used for structural analysis but employed to formulate a new spring element named the NNSE to model single piles in pile-supported structures. This NNSE can be seamlessly implemented within the existing LFEM framework to analyze pile-supported structures, eliminating the dense mesh requirement for single piles and thereby significantly improving the computational efficiency. Extensive examples are provided to verify the effectiveness of the proposed method, indicating its potential in promoting the second-order analysis method to the design of pile-supported structures.

Dumbbell-Shaped, Block-Graft Copolymer with Aligned Domains for High-performance Hydrocarbon Polymer Electrolyte Membranes.

Given the environmental concerns surrounding fluoromaterials, the use of high-cost perfluorinated sulfonic acids (PFSAs) in fuel cells and water electrolysis contradicts the pursuit of clean energy systems. Herein, we present a fluorine-free dumbbell-shaped block-graft copolymer, derived from the cost-effective triblock copolymer poly(styrene-b-ethylene-co-butylene-b-styrene) (SEBS), for polymer electrolyte membranes (PEMs). This unique polymer shape led to the alignment of the hydrophobic-hydrophilic domains along a preferred orientation, resulting in the construction of interconnected proton channels across the membrane. A bicontinuous network allowed efficient proton transport with reduced tortuosity, leading to an exceptional ionic conductivity (249 mS cm-1 at 80 °C and 90% relative humidity (RH)), despite a low ion exchange capacity (IEC; 1.41). Furthermore, membrane-electrode assembly (MEA) prepared with our membrane exhibited stable performance over a period of 150 h at 80 °C and 30% RH. This study demonstrates a novel polymer structure design and highlights a promising outlook for hydrocarbon PEMs as alternatives to PFSAs.

Dumbbell‐Shaped, Block‐Graft Copolymer with Aligned Domains for High‐performance Hydrocarbon Polymer Electrolyte Membranes

Given the environmental concerns surrounding fluoromaterials, the use of high‐cost perfluorinated sulfonic acids (PFSAs) in fuel cells and water electrolysis contradicts the pursuit of clean energy systems. Herein, we present a fluorine‐free dumbbell‐shaped block‐graft copolymer, derived from the cost‐effective triblock copolymer poly(styrene‐b‐ethylene‐co‐butylene‐b‐styrene) (SEBS), for polymer electrolyte membranes (PEMs). This unique polymer shape led to the alignment of the hydrophobic‐hydrophilic domains along a preferred orientation, resulting in the construction of interconnected proton channels across the membrane. A bicontinuous network allowed efficient proton transport with reduced tortuosity, leading to an exceptional ionic conductivity (249 mS cm‐1 at 80 °C and 90% relative humidity (RH)), despite a low ion exchange capacity (IEC; 1.41). Furthermore, membrane‐electrode assembly (MEA) prepared with our membrane exhibited stable performance over a period of 150 h at 80 °C and 30% RH. This study demonstrates a novel polymer structure design and highlights a promising outlook for hydrocarbon PEMs as alternatives to PFSAs.

Tuning the potentials of aluminum phosphide nanotube photocatalyst for wastewater treatment through band gap engineering: a DFT study

Abstract The photocatalytic properties of semiconductor materials, which are controllable through the design of the bandgap structure, make them a promising catalyst for wastewater treatment. This work investigated the photocatalytic properties of single-walled aluminum phosphide nanotube (SWAlPNT) doped with different concentrations of boron (B) atoms for wastewater treatment. Analysis of the structural, electronic and optical properties of the SWAlPNT photocatalyst was performed using the density functional theory approach in terms of plane wave basis set and pseudopotential. The SWAlPNT was found to be stable to B doping with 3.6% and 7.1% concentrations. Cohesive energy decreases with an increase in concentration of dopant which results in efficient thermal stability. An indirect band gap value of 1.4 eV was obtained with B-doped SWAlPNT with 3.6% concentration which agreed with band gaps of other photocatalysts used for wastewater purification. Analysis using optical absorption spectra revealed that 3.6% B-doped system absorbs visible light while 7.1% doped system absorbs both visible and ultraviolet light. This study found both 3.6% and 7.1% B-doped SWAlPNT as suitable photocatalysts for wastewater treatment under solar irradiation, while the 3.6% B-doped system shows relatively better performance for wastewater treatment.

Molecular design of free volume structure in thermally rearranged polybenzoxazole membranes for gas separation studied by positron annihilation

AbstractIn this work, 2,2‐bis(3‐amino‐4‐hydroxyphenyl) hexafluoropropane (APAF) was used as the fixed diamine monomer, and 4,4′‐(hexafluoroisopropylidene) diphthalic anhydride (6FDA), 4,4′‐oxydiphthalic anhydride (ODPA), 3,3′,4,4′‐biphenyltetracarboxylic diandhydride (BPDA) and pyromellitic dianhydride (PMDA) were selected as four different dianhydride monomers, respectively, to prepare the thermally rearranged polybenzoxazole (TR‐PBO) gas separation membranes with different structures via a thermal rearrangement reaction at 450°C. The microstructure of TR‐PBO membranes was investigated using X‐ray diffraction and positron annihilation spectroscopy. All the TR‐PBO membranes exhibit bimodal free volume structure, containing ultramicropores (<0.7 nm) and micropores (<2 nm) with size of 3.6–4.6 and 7.6–8.4 Å, respectively. As the steric hindrance of the bridging groups in the dianhydride monomers increases, the radius and number of pores in the membranes increases, leading to an increase in fractional free volume (FFV). The pure gas permeation test shows a positive correlation between gas permeability and FFV in the TR‐PBO membranes, indicating that an increase in FFV is favorable for the diffusion of gas molecules. Particularly, the ultramicropores play a decisive role on the gas selectivity. All the TR‐PBO membranes exhibit excellent gas permeaselectivity. Among them, the H2/CH4 separation performance of APAF‐6FDA and APAF‐ODPA membranes approaches the 2008 Robeson upper bound, which is due to the high number of both micropores and ultramicropores. Our results demonstrate that the free volume structure of polymer membranes can be designed by selecting monomers with different structures and utilizing thermal rearrangement reactions, allowing for the preparation of gas separation membranes with high permeability and selectivity.

Comparative Analysis of Flood Estimation using Log-Pearson Type III and Gumbel Max Models in the Cauvery River, India

Flooding is one of the most destructive global disasters in scale, geographical extent, property and life loss, and population displacement. The Cauvery River is one of the flood vulnerable rivers in the Peninsular region of India. At-site flood frequency analysis is performed using flow data obtained at the Kodumudi gauged site in the Cauvery River. Log Pearson Type III and Gumbel Max distribution models are used in the present study to estimate peak floods for different return periods. The Central Water Commission provides the annual maximum discharge for the Kodumudi gauged site over 39 years (1980-2018). The goodness of fit test employing the Kolmogorov-Smirnov and Anderson- Darling tests, reveals that Log-Pearson Type III best estimates peak floods in the study area. The peak floods predicted by Log-Pearson Type III for return periods 2, 5, 10, 25, 50, 100, 200, and 500 years are approximately 929, 1886, 2998, 5303, 8002, 11929, 17633, and 29228 cumecs. Hydraulic structures can be designed in the region based on 100-year flood. The present research could help with flooding management approaches, vulnerability analyses, and hydraulic structure design in the study region.

Inorganic Composition Modulation of Solid Electrolyte Interphase for Fast Charging Lithium Metal Batteries.

The solid electrolyte interphase (SEI) with lithium fluoride (LiF) is critical to the performance of lithium metal batteries (LMBs) due to its high stability and mechanical properties. However, the low Li ion conductivity of LiF impedes the rapid diffusion of Li ions in the SEI, which leads to localized Li ion oversaturation dendritic deposition and hinders the practical applications of LMBs at high-current regions (>3 C). To address this issue, we introduce a fluorophosphated SEI rich with fast ion-diffusing inorganic grain boundaries (LiF/Li3P). By utilizing a sol electrolyte that contains highly dispersed porous LiF nanoparticles modified with phosphorus-containing functional groups, we construct a fluorophosphated SEI and demonstrate the presence of electrochemically-active Li within these fast ion-diffusing grain boundaries (GBs-Li) that are non-nucleated, ensuring the stability of the Li || NCM811 cell for over 1,000 cycles at fast-charging rates of 5 C (11mA cm-2). Additionally, we fabricate a practical, long cycling, and intrinsically safe LMB pouch cell with high energy density (400Wh kg-1). Our work reveals how SEI components and structure design can enable fast-charging LMBs. This article is protected by copyright. All rights reserved.

Design of smart magnetic thin-sheet structure based wireless sensors-array arrangement for intraoral-pressure sensing approach

During orthodontic treatments, orthodontists want to simultaneously measure different kinds of intraoral pressure of a patient to determine a suitable orthodontic treatment plan for the patient. To achieve this, an intraoral pressure sensors-array with a specific arrangement in the oral cavity is needed. Hence, in this paper, we design a smart magnetic thin-sheet structure based wireless sensors-array arrangement for intraoral-pressure sensing for orthodontics to determine the above suitable treatment plan. In general, the sensors-array consists of multiple sensing modules. Each module consists of two parts: the first part is a transmitting/receiving electromagnet which is connected to a reference electromagnet in a balanced inductance bridge configuration while the second part is a smart magnetic thin-sheet structure based high-permeable sensing diaphragm. A voltage input is applied to the reference electromagnet and transmitting/receiving electromagnet, while the voltage output is measured from the transmitting/receiving electromagnet, respectively (the transmitting/receiving electromagnet can transmit the magnetic flux as well as receive or sense the change of magnetic flux). When the sensing diaphragm (which is placed in proximity to the transmitting/receiving electromagnet) undergoes a displacement, the gap between the sensing diaphragm and transmitting/receiving electromagnet changes. This subsequently changes surrounding magnetic flux, and consequently results in a change in magnetic reluctance between the sensing diaphragm and transmitting/receiving electromagnet. Thus, the voltage output of the transmitting/receiving electromagnet is changed accordingly. Based on this operation principle, furthermore, we use multiple transmitting/receiving electromagnets to form a compact (specifically arranged) sensors-array. The results show that specifically arranged sensors-array can provide measurement results in multiple points in the oral cavity to the orthodontists, as a simplified decision-making reference for the orthodontists to determine the clinical treatment plan for patients.

Solvation structure design for stabilizing MXene in transition metal ion solutions

AbstractAlthough MXene has attracted great interest in diverse fields, it is susceptible to oxidation in water (H2O) with transition metal ions such as Co2+, Fe2+, and Cu2+, which is pronounced at high temperatures. This impedes the preparation of MXene‐based composites and their functional applications. Here, this study revealed that Co2+ increases the maximum and average atomic charge of H in H2O to improve the reactivity of H2O, which leads to the fact that Co2+ catalyzes the oxidation of Ti3C2Tx MXene. Furthermore, the addition of N,N‐dimethyl formamide (DMF) reduces the H2O activity and improves the oxidation stability of Ti3C2Tx in the presence of Co2+ via preferentially forming coordination bonds with Co2+. This strategy is also effective in enhancing the oxidation tolerance of Ti3C2Tx to Fe2+ in H2O. Moreover, it is feasible to enhance the oxidation stability of Ti2CTx MXene in H2O with the existence of Co2+. By virtue of these, the CoO/Ti3C2Tx composite was successfully prepared without obvious Ti3C2Tx oxidation, which is desirable to harness the advantages of Ti3C2Tx as the complementary component for lithium‐ion batteries. This work provides a straightforward paradigm to enhance the oxidation resistance of MXene in H2O in the presence of transition metal ions and at high temperatures, which opens a new vista to use MXene for target applications.

Flexible Janus Black Silicon Photothermal Conversion Membranes for Highly Efficient Solar-Driven Interfacial Water Purification.

Photothermal conversion materials are critical in the development of solar-driven interfacial evaporation techniques; however, achieving a high energy conversion efficiency remains challenging owing to the high cost and instability of light-absorbing materials, in addition to the difficulties of simultaneously improving light absorption while suppressing heat loss. A black silicon (Si) powder with a porous structure was prepared by chemical etching of a low-cost commercial micron-sized Al-Si alloy, and a flexible Janus black Si photothermal conversion membrane was constructed. The partially broken spherical particles and porous structure obtained after etching enhanced the refraction of light from the Si powder, imparting the prepared membrane with an average light absorption rate of 95.95% over the solar spectrum. Evaporation from the membrane increased the intermediate water content and reduced the equivalent evaporation enthalpy. The thermal conduction loss was inhibited through a one-dimensional water transport structure, and the membrane achieved a water evaporation rate of 2.17 kg m-2 h-1 and a photothermal efficiency of 94.95% under 1 sun illumination. Benefiting from the broadband absorption and high photothermal efficiency of black Si powder, surface modification of hydrophobic polydimethylsiloxane, and directional salt-out structure design, the evaporation rate of the Janus black Si membrane-based system in a 10% NaCl solution was maintained >2.10 kg m-2 h-1 after 7 days of continuous evaporation cycles. The removal rate of metal ions from simulated seawater and from practical wastewater containing complex heavy metals reached >99.9%, indicating the promising potential of black Si membrane for application in solar-driven interfacial water purification.

Curtailing of Torque Ripples in Switched Reluctance Motor using Nano Soft Ferrite Rotor

Switched Reluctance motors (SRM) enthralled many researchers due to their coherent structure and sturdy design switched reluctance motors are, robust, reliable, fault tolerated, efficient, and maximum temperature resistant when compared to other conventional motors. The drift in the power electronic converters enhances the usage of SRM, stator and rotor consisting of projected inward and outward poles the gap between the stator and rotor causes harmonics which cause torque ripples which are deteriorating SRM drives. In this paper, a ferrite rotor is considered which is composed by the different material like nickel, manganese, copper, ferric, and aluminium by manoeuvring combustion of solution and gel method. By availing ferrite material magnetizing and demagnetizing can be done quickly which is essential for SRM rotor.

A bionic bird jumping grasping structure design based on stm32 development board control

During takeoff and landing, birds bounce and grab with their legs and feet. In this paper,the lower limb structure of the bionic bird is designed with reference to the function of jumping and grasping, and the PID algorithm based on the development module of stm32 development board is used to speed control the lower limb driving element, so that the motor and the bishaft steering gear move with the rate change of sine wave. According to the speed of grasping response time and the size of grasping force, the structure of the bionic bird paw is designed. Based on the photosensitive sensor fixed in the geometric center of the foot, the grasping action of the lower limb mechanism is intelligently controlled. Finally, the kinematic verification of the lower limb structure is carried out by ADAMS. Experiments show that the foot structure with four toes and three toes is more conducive to maintaining the stability of the body while realizing the fast grasping function. In addition, it can effectively improve the push-lift ratio of the bionic ornithopter by adjusting the sinusoidal waveform rate of the motor speed.

Unlocking the potential of rooftop solar panels: An incentive rate structure design

With the continuous maturity of distributed generation technology, rooftop solar panels have come to play an increasingly critical role in the construction of future energy systems. However, there remains an open question as to how to design adequate rate structure and provide proper incentives for distributed solar production. In this paper, we propose an incentive rate structure for rooftop solar panels to fairly unlock the potential of such distributed energy resources. The interaction of residential consumers and utilities is formulated as a tri-level optimization model to evaluate the impact of the rate structure design on the welfare transfer and investment behavior of residential consumers. An incentive rate structure is designed in which the supply-side effects of rooftop solar panel investment are considered by explicitly modeling wholesale market dynamics. Contrary to conventional belief, we indicate that the integration of rooftop solar panels can increase the expected profits of the utility company in some usual cases. Case studies demonstrate that through adequate rate structure design, the market operator can achieve the established social goals while balancing the welfare transfer effect among different market entities. Hopefully, our work can provide novel insights and a theoretical reference for the relevant policy design.

Constructing Self-Healing Polydimethylsiloxane through Molecular Structure Design and Metal Ion Bonding

Self-healing polydimethylsiloxane (PDMS) has garnered significant attention due to its potential applications across various fields. In this study, a functionalized modification of PDMS containing di-aminos was initially conducted using 2,6-pyridinedicarbonyl chloride to synthesize pyridine-PDMS (Py-PDMS). Subsequently, rare earth metal europium ions (Eu3+) were incorporated into Py-PDMS. Due to the coordination interaction between Eu3+ and organic ligands, a coordination cross-linking network was created within the Py-PDMS matrix, resulting in the fabrication of Eu3+-Py-PDMS elastomer. At a molar ratio of Eu3+ to ligands of 1:1, the tensile strength of Eu3+-Py-PDMS reached 1.4 MPa, with a fracture elongation of 824%. Due to the dynamic reversibility of coordination bonds, Eu3+-Py-PDMS with a metal-to-ligand molar ratio of 1:2 exhibited varying self-healing efficiencies at different temperatures. Notably, after 4 h of repair at 60 °C, its self-healing efficiency reached nearly 100%. Furthermore, the gas barrier properties of Eu3+-Py-PDMS with a molar ratio of 1:1 was improved compared with that of Eu3+-Py-PDMS with a molar ratio of 1:1. This study provides an effective strategy for the design and fabrication of PDMS with high mechanical strength, high gas barrier properties, and exceptional self-healing efficiency.

Structure Design and Heat Transfer Performance Analysis of a Novel Composite Phase Change Active Cooling Channel Wall for Hypersonic Aircraft

Efficient and stable heat dissipation structure is crucial for improving the convective heat transfer performance of thermal protection systems (TPSs) for hypersonic aircraft. However, the heat dissipation wall of the current TPS is limited by a single material and structure, inefficiently dissipating the large amount of accumulated heat generated during the high-speed maneuvering flight of hypersonic aircraft. Here, a convection cooling channel structure of TPS is proposed, which is an innovative multi-level structure inspired by the natural honeycomb. An active cooling channel (PCM-HC) is designed by using a variable-density topology optimization method and filled with phase change material (PCM). Numerical simulations are used to investigate the thermal performance of the PCM-HC wall, focusing on the influence of PCM properties, structural geometric parameters, and PCM types on heat transfer characteristics. The results demonstrate that the honeycomb-like convection cooling channel wall, combined with PCM latent heat of phase change, exhibits superior heat dissipation capability. With a heat flux input of 50 kW/m2, the maximum temperature on the inner wall of PCM-HC is reduced by 12 K to 20 K. Different PCMs have opposing effects on heat transfer performance due to their distinct thermophysical properties. This work can provide a theoretical basis for the design of high-efficiency cooling channel, improving the heat dissipation performance in the TPS of hypersonic aircraft.

Design of a metal additive manufactured aircraft seat leg using topology optimization and part decomposition

Purpose The lightweight design of aircraft seats can significantly improve fuel efficiency and reduce greenhouse gas emissions. Metal additive manufacturing (MAM) can produce lightweight topology-optimized designs with improved performance, but limited build volume restricts the printing of large components. The purpose of this paper is to design a lightweight aircraft seat leg structure using topology optimization (TO) and MAM with build volume restrictions, while satisfying structural airworthiness certification requirements. Design/methodology/approach TO was used to determine a lightweight conceptual design for the seat leg structure. The conceptual design was decomposed to meet the machine build volume, a detailed CAD assembly was designed and print orientation was selected for each component. Static and dynamic verification was performed, the design was updated to meet the structural requirements and a prototype was manufactured. Findings The final topology-optimized seat leg structure was decomposed into three parts, yielding a 57% reduction in the number of parts compared to a reference design. In addition, the design achieved an 8.5% mass reduction while satisfying structural requirements for airworthiness certification. Originality/value To the best of the authors’ knowledge, this study is the first paper to design an aircraft seat leg structure manufactured with MAM using a rigorous TO approach. The resultant design reduces mass and part count compared to a reference design and is verified with respect to real-world aircraft certification requirements.

Rational design of the aerodynamic rudder structure taking into account strength, rigidity and aeroelastic stability

The paper considers a design process of an aerodynamic rudder, which structure comprises the skin of constant thickness, a load-bearing structure and a trimmed nose that plays the role of an anti-flutter balancer. The aim of the work is to set and solve the design problem of a rational structural and technological solution of the rudder that meets the requirements of strength, rigidity, aeroelastic stability and minimum mass. To solve this problem, a design algorithm for the rudder, using topological and parametric optimization, is proposed. The main parameters of the design area and the trimmed nose required for topological optimization are determined. The ANSYS Workbench software package was used for the finite element analysis and topological optimization. Based on the results of optimization, post-processing was carried out. A structural and technological solution, that combines structural layouts with constant and variable width of the trimmed nose, was proposed. An analysis of the stress-strain state was carried out, and it was found that the designed structure meets the strength requirements for the given design case. A scheme for solving the parametric optimization problem of the rudder under the condition of aeroelastic stability is proposed. Within the framework of solving this problem, a flutter study was conducted, using a multi-mode model, which makes it possible to study the rudder and body-rudder flutter forms of an unmanned aerial vehicle (UAV) equipped with aerodynamic rudders. The results of the flutter study for the design mode of the UAV flight are obtained in the form of dependencies of the critical flutter velocity and frequency on the average width of the trimmed nose. The analysis of these dependencies allowed us to derive the optimal values of the trimmed nose parameters from the minimum weight condition for two rudder configurations: with a constant and variable width of the trimmed nose.