Search results

This paper aims to investigate the rebound process and the secondary-impact process of the fuselage section that occurs in the actual crash events.

A full-scale three-dimensional finite element model of the fuselage section was developed to carry out the dynamic simulations. The rebound process was simulated by removing the impact surface at a certain point, while the secondary-impact process was simulated by striking the impact surface against the fuselage bottom after the first impact.

For the rebound process, the fuselage structure restores deformation due to the springback of the fuselage bottom, and it results in structural vibration of the fuselage section. For the secondary-impact process, the fuselage deformation is similar with that of the single impact process, indicating that the intermittent impact loading has little influence on the overall deformation of the fuselage section. The strut failure is the determining factor to the acceleration responses for both the rebound process and the secondary-impact process.

The rebound process and the secondary-impact process, which is difficult to study by experiments, was investigated by finite element simulations. The structure deformations and acceleration responses were obtained, and they can provide guidance for the crashworthy design of fuselage structures.

This research first investigated the rebound process and the secondary-impact process of the fuselage section. The absence of the ground load and the secondary-impact was simulated by controlling the impact surface, which is a new simulating method and has not been used in the previous research.

This study aims to explore a methodology based on the Kano model. And use this method to determine user requirement attributes in the field of school uniform customization. To construct a set of processes that can be used as a reference for constructing a clothing customization platform.

An optimized quantitative Kano model was applied. Initially, a survey was conducted to assess the current market for customized school uniforms in China. Subsequently, a Kano attribute questionnaire was developed, and experts from both supply and procurement sectors were invited to evaluate it. This was followed by categorizing user demands based on the Kano model’s evaluation criteria and conducting a validity analysis using Cronbach’s alpha coefficient. The priority ranking of user demands was determined through a sensitivity analysis of better-worse coefficients. Ultimately, a platform was established, and a fuzzy comprehensive evaluation was conducted.

Regarding user demands, procurement-side demand elements prioritize modular design, fabric libraries and online reviews. In contrast, supply-side demand elements focus on style product libraries, layout adaptation to user habits and the preview effects of 3D models. Elements such as qualification verification, personal information uploading, design draft archiving and main tag categorization have a lesser impact on user satisfaction.

The results of the study provide a complete methodological reference for the construction of a garment customization platform. By applying the Kano model, this study categorizes and filters the demands of users for school uniform customization design platforms in China and establishes a 3D virtual display platform aimed at improving user satisfaction.

The purpose of this paper is to improve the crashworthiness of aircraft by using the strut system as an energy absorption device without redesigning other components.

The novel strut system consists of metal stepped thin-walled tubes and articulated connecting hinges. The strut is suffering axial load during impact process for rotating of hinges, and the metal stepped tube has an inversion failure behaviour.

The metal stepped tube has lower initial impact load and more stable failure behaviour. The geometrical factors have a great influence on the impact load and energy absorption efficiency. The best length ratio between upper and lower sections is about 2:1 and 1:1 for the metal stepped circular and square tubes, respectively.

The metal stepped tube with inversion mechanism is suitable for aircraft strut system to improve crashworthiness performance.

A new strut system is provided using metal inversion failure stepped tubes and articulated connecting hinges to improve crash worthiness of aircraft.

The purpose of this paper is to understand individual academics’ perception, attitudes and participation in Open Access Publishing and open scholarship and revisit some principles and designs of openness in academic publishing from the perspective of creative end-users, which helps to increase the sustainability and efficiency of open models.

This paper draws on a case study of China and empirical data collected through semi-structured interviews with a wide range of academics and stakeholders.

A separation between the communication and certification functions of publishing is identified: open initiatives are valued for efficient and interactive communication while traditional publishing still dominates the legitimacy of research publications, which leads to the quandary of individual academics operating within the transitional landscape of scholarly communication.

Practical recommendations for sustainable and efficient openness are derived from discussions on the difficulties associated open/social certification and the shifting maxims that govern academics from “publish or perish” to “be visible or vanish”.

“Openness” is defined in broad sense integrating Open Access and open scholarship to comprehensively reflect individual academics’ views in the transitional landscape of academic publishing. The research findings suggest that new open approaches are needed to address the evolving tension and conflicts between communication and certification.

The internet is transforming possibilities for creative interaction, experimentation and cultural consumption in China and raising important questions about the role that “publishers” might play in an open and networked digital world. The purpose of this paper is to consider the role that copyright is playing in the growth of a publishing industry that is being “born digital”.

The paper approaches online literature as an example of a creative industry that is generating value for a wider creative economy through its social network market functions. It builds on the social network market definition of the creative industries proposed by Potts et al. and uses this definition to interrogate the role that copyright plays in a rapidly‐evolving creative economy.

The rapid growth of a market for crowd‐sourced content is combining with growing commercial freedom in cultural space to produce a dynamic landscape of business model experimentation. Using the social web to engage audiences, generate content, establish popularity and build reputation and then converting those assets into profit through less networked channels appears to be a driving strategy in the expansion of wider creative industries markets in China.

At a moment when publishing industries all over the world are struggling to come to terms with digital technology, the emergence of a rapidly‐growing area of publishing that is being born digital offers important clues about the future of publishing and what social network markets might mean for the role of copyright in a digital age.

The purpose of this paper is to explore discrepancies between transfer provisions in the US model BIT, employed as a working text in the ongoing China‐USA BIT negotiations, and relevant Articles of the Agreement of the IMF, to which both China and the USA are signatories, with a view to advising on China's possible strategies for negotiation.

The approach taken is doctrinal and comparative analysis and treaty interpretation of the US model BIT, the Articles of the Agreement of the IMF, the Chinese model BIT and some earlier versions of these instruments.

A detailed analysis of several major discrepancies between these instruments finds that a differentiated treatment of capital transfers and current transfers is desirable and, in respect of current transfers, a properly formulated “temporary derogation” exception should be adopted.

The paper conducts a unique substantial comparison of two most influential instruments governing transfer of funds in international investments. It reveals the common rationale shared by the transfer provisions under both instruments.

The purpose of this paper is establishing a general mathematical model and theoretical design rules for 3D printing of biomaterials. Additive manufacturing of biomaterials provides many opportunities for fabrication of complex tissue structures, which are difficult to fabricate by traditional manufacturing methods. Related problems and research tasks are raised by the study on biomaterials’ 3D printing. Most researchers are interested in the materials studies; however, the corresponded additive manufacturing machine is facing some technical problems in printing user-prepared biomaterials. New biomaterials have uncertainty in physical properties, such as viscosity and surface tension coefficient. Therefore, the 3D printing process requires lots of trials to achieve proper printing parameters, such as printing layer thickness, maximum printing line distance and printing nozzle’s feeding speed; otherwise, the desired computer-aided design (CAD) file will not be printed successfully in 3D printing.

Most additive manufacturing machine for user-prepared bio-material use pneumatic valve dispensers or extruder as printing nozzle, because the air pressure activated valve can print many different materials, which have a wide range of viscosity. We studied the structure inside the pneumatic valve dispenser in our 3D heterogeneous printing machine, and established mathematical models for 3D printing CAD structure and fluid behaviors inside the dispenser during printing process.

Based on theoretical modeling, we found that the bio-material’s viscosity, surface tension coefficient and pneumatic valve dispenser’s dispensing step time will affect the final structure directly. We verified our mathematical model by printing of two kinds of self-prepared biomaterials, and the results supported our modeling and theoretical calculation.

For a certain kinds of biomaterials, the mathematical model and design rules will have unique solutions to the functions and equations. Therefore, each biomaterial’s physical data should be collected and input to the model for specified solutions. However, for each user-made 3D printing machine, the core programming code can be modified to adjust the parameters, which follows our mathematical model and the related CAD design rules.

This study will provide a universal mathematical method to set up design rules for new user-prepared biomaterials in 3D printing of a CAD structure.

The bridge expansion joint (BEJ) is a key device for accommodating spatial displacement at the beam end, and for providing vertical support for running trains passing over the gap between the main bridge and the approach bridge. For long-span railway bridges, it must also be coordinated with rail expansion joint (REJ), which is necessary to accommodate the expansion and contraction of, and reducing longitudinal stress in, the rails. The main aim of this study is to present analysis of recent developments in the research and application of BEJs in high-speed railway (HSR) long-span bridges in China, and to propose a performance-based integral design method for BEJs used with REJs, from both theoretical and engineering perspectives.

The study first presents a summary on the application and maintenance of BEJs in HSR long-span bridges in China representing an overview of their state of development. Results of a survey of typical BEJ faults were analyzed, and field testing was conducted on a railway cable-stayed bridge in order to obtain information on the major mechanical characteristics of its BEJ under train load. Based on the above, a performance-based integral design method for BEJs with maximum expansion range 1600 mm (±800 mm), was proposed, covering all stages from overall conceptual design to consideration of detailed structural design issues. The performance of the novel BEJ design thus derived was then verified via theoretical analysis under different scenarios, full-scale model testing, and field testing and commissioning.

Two major types of BEJs, deck-type and through-type, are used in HSR long-span bridges in China. Typical BEJ faults were found to mainly include skewness of steel sleepers at the bridge gap, abnormally large longitudinal frictional resistance, and flexural deformation of the scissor mechanisms. These faults influence BEJ functioning, and thus adversely affect track quality and train running performance at the beam end. Due to their simple and integral structure, deck-type BEJs with expansion range 1200 mm (± 600 mm) or less have been favored as a solution offering improved operational conditions, and have emerged as a standard design. However, when the expansion range exceeds the above-mentioned value, special design work becomes necessary. Therefore, based on engineering practice, a performance-based integral design method for BEJs used with REJs was proposed, taking into account four major categories of performance requirements, i.e., mechanical characteristics, train running quality, durability and insulation performance. Overall BEJ design must mainly consider component strength and the overall stiffness of BEJ; the latter factor in particular has a decisive influence on train running performance at the beam end. Detailed BEJ structural design must stress minimization of the frictional resistance of its sliding surface. The static and dynamic performance of the newly-designed BEJ with expansion range 1600 mm have been confirmed to be satisfactory, via numerical simulation, full-scale model testing, and field testing and commissioning.

This research provides a broad overview of the status of BEJs with large expansion range in HSR long-span bridges in China, along with novel insights into their design.

This paper aims to present an evaluation method for energy-absorption characteristics of thin-walled composite structures with random uncertain parameters.

The mechanical properties of T700/3234 are obtained by material performance tests and energy-absorption results are obtained by quasi-static crushing tests of thin-walled composite circular tubes. The indicators of triggering specific load (TSL) and specific energy absorption (SEA) are introduced and calculated to determine the energy-absorption characteristics and validate the probability finite element analysis model. The uncertainty in the parameters contain the machining tolerance for the thickness and inner diameter of composite circular tubes and are associated with the composite material system. The Plackett–Burman method is used to choose the measurement parameters. Then, the response surface method is used to build a second-order function of random uncertain parameters versus TSL/SEA, and the Monte Carlo method is finally used to obtain the probabilities of TSL and SEA.

The finite element models can accurately simulate the initial peak load, load-displacement curve and SEA value. The random uncertain parameter method can be used to evaluate the energy-absorption characteristics of thin-walled composite circular tubes.

The presented evaluation method for energy-absorption characteristics of thin-walled composite structures is an approach that considers uncertain parameters to increase the simulation accuracy and decrease the computational burden.

This methodology considers uncertain parameters in evaluating the energy-absorption characteristics of thin-walled composite structures, and this methodology can be applied to other thin-walled composite structures.