Laser-cutting Technology Research Articles

Exploring the modern Qipao through the lens of U.S. generation Z consumers

ABSTRACT This study investigates U.S. Generation Z consumers’ preferences and buying behaviours toward Qipao-inspired clothing, addressing a gap in existing research on culturally inspired apparel for young, diverse consumers. Using a quantitative approach, five Qipao-inspired designs were developed based on 2023 fashion trends and traditional Chinese elements. Consumer insights were gathered through an online survey. Findings show that modern Qipao A was the most favoured design, with high ratings for its blend of traditional and contemporary elements. Additionally, the use of laser-cutting technology, colour symbolism, and details such as the keyhole neckline were identified as resonant features among Generation Z. This study offers valuable guidance for fashion designers and retailers aiming to adapt traditional Chinese clothing to meet contemporary tastes, with implications for cultural preservation and innovation. Future research should expand to diverse ethnic groups and explore additional generational cohorts to deepen understanding of how cultural apparel resonates across audiences.

Effect of Fiber-Laser Parameters on Cutting Accuracy of Thin and Thick S355JR Structural Steel Plates

Fiber lasers, the latest laser-cutting technology, are notable for their high process efficiency, cutting precision, and high cutting quality for thin materials. However, the quality of the cut significantly decreases when machining thicker materials. For now, this is a challenge for the metalworking industry. This study investigated the effects of laser power, cutting speed, and auxiliary gas pressure on the fiber-laser cutting quality of 4 and 6 mm thick S355JR steel plates. To evaluate the influence of cutting parameters on cutting quality, surface roughness, dimensional accuracy and cut taper were measured. A microscopic analysis of the laser cuts was performed, revealing the heat-affected zone, transition zone and unaffected base-material zone. Research results show that laser cutting is a complex process, and the correct choice of cutting parameters greatly influences the cutting performance and final quality. An artificial neural network was created and trained using the results from measuring the quality characteristics to achieve optimum cutting quality. The accuracy of the optimization model was assessed by control samples, which were cut using calculated optimum parameters. The actual values of the quality characteristics only slightly differ from the predicted values, showing that the optimization model is suitable for selecting cutting parameters.

A cradle-to-site life cycle analysis of laser-cut passing-through tubular joints under different seismic conditions

Steel circular hollow sections (CHS) offer a number of advantages compared to their open section counterparts such as better resistance under tension, compression, bending in all directions and an overall reduction of structural weight, required material for corrosion and fire protection. Nevertheless, the traditional methods to connect open section beams to CHS columns often demand a significant amount of fabrication work, leading to high expenditure and resource consumption – therefore limiting their use in the current industry. These issues can be solved with an automatized joint fabrication. To that purpose, this article proposes two innovative “passing-through” I-to-CHS joints, achieved via laser cutting technology (LCT). Experimental and numerical studies were conducted to assess the joint fabrication aspects as well as the structural performance of the proposed joints. The results showed that the proposed joints can offer respectively 2.5- and 10-times larger strength and stiffness properties compared to a conventional directly welded I-to-CHS joint having similar section properties for the beam and the column. However, this study focuses on the environmental sustainability and economic feasibility of the proposed joints. A cradle-to-site life cycle analysis is conducted using multi-storey frame structures. The environmental and economic impact of the proposed joints are compared with different types of existing I-to-CHS joints in order to assess their possible benefits and limitations. Thanks to the savings in the raw material, surface treatment and transportation resources, it could be stated that, the passing-through approach with LCT offers approximately 32−42% reduction in the construction and fabrication costs of the multi-storey structures while reducing the CO2 emissions by 24−28%, compared to the directly welded I-to-CHS joints.

Strength of connections between SHS columns and through plates

AbstractThe use of Square‐Hollow‐Section (SHS) members as columns of moment‐resisting frames is a very interesting solution thanks to several benefits they can provide. However, especially in Europe and the USA, the use of SHS columns is limited by the complexity related to the realisation of beam‐to‐column connections. Nevertheless, the recent use in civil engineering of Laser Cutting Technology (LCT) has offered the opportunity to manufacture welded connections by properly cutting the tubular profile with the imprint of the cross‐section shape of the double‐tee member. Such a solution is an improved alternative to the joint with the I‐beam welded to the external surface of the hollow profile since higher flexural strength and stiffness can be provided. Considering the importance of such a topic, this connection is currently being studied at the University of Salerno within the framework of the component method approach.In this view, the research activity discussed in this paper deals with studying the monotonic behaviour experienced by welded connections between SHS tubes and through‐all plates. In fact, this component is intended to be representative of the actions applied on the tube by each of the beam flanges of a double‐tee profile. In particular, this nodal component has been identified and studied thanks to numerical simulations and theoretical approaches, leading to analytical design formulations.

I‐beam‐to‐SHS column moment resisting joints using passing‐through plates under opposite bending moments: numerical and analytical studies

AbstractAs thin walled HSS columns are very flexible, they usually exhibit excessive deformation when resisting a bending moment or transverse loads. Adding exterior/interior diaphragms is one way to remedy the problem. Another option that can significantly increase strength and stiffness is to allow passing plates through the hollow column by means of Laser Cutting Technology (LCT). This solution was tested on CHS columns within the RFCS LASTEICON project. The first outcomes were promising. One of LASTTS new RFCS project's overarching concerns is to enlarge the range of application of the passing‐through solution onto SHS columns.The goal of this research paper is to present the behaviour of I‐beam‐to‐SHS column moment resisting joints using passing‐through plates under opposite bending moments. First, a solid‐based finite element model is presented. This model is used to conduct a sensitivity analysis with different SHS column and passing plates geometry. The failure mode is resulting contribution of both weld/tube‐wall tearing in tension, and chord face crushing in compression. Analytical models are developed in an attempt to ascertain the bending resistance and initial rotational stiffness of this new type of connections.

Experimental Assessment of the Behavior of Tubular Truss Girder Joints Fabricated with Laser Cutting Technology

Directly welded truss girder joints result in high-stress development on the tube wall, which leads to increased chord thicknesses, requires extra welding, and presents detailing difficulties. Laser cutting technology (LCT) allows us to make precise cuts and pass through the truss members, welding the connection on the two sides. This can reduce geometrical imperfections, and, as a result, it increases joint strength. This paper presents truss girder joints developed with LCT that can develop higher resistance to static gravity loads with respect to conventional connections thanks to the pass-through solution. An extensive experimental campaign (31 specimens) has been carried out involving the monotonic gravity loading of several truss specimens to simulate their in-service conditions. Different truss typologies are tested (Warren and Pratt) using circular and square hollow section profiles, at different scales (full-scale and small-scale). The results showed that Warren-type structures with LCT connection solutions had a 20% higher strength with respect to the equivalent structures with directly welded joints. Furthermore, the correlation between the different failure modes and joint parameters (e.g., angles and distance between brace members) has been discussed.

Laser-Cutted Epidermal Microfluidic Patch with Capillary Bursting Valves for Chronological Capture, Storage, and Colorimetric Sensing of Sweat.

Flexible wearable microfluidic devices show great feasibility and potential development in the collection and analysis of sweat due to their convenience and non-invasive characteristics in health-level feedback and disease prediction. However, the traditional production process of microfluidic patches relies on resource-intensive laboratory and high-cost facilities. In this paper, a low-cost laser-cutting technology is proposed to fabricate epidermal microfluidic patches for the collection, storage and colorimetric analysis of sweat. Two different types of capillary bursting valves are designed and integrated into microchannel layers to produce two-stage bursting pressure for the reliable routing of sweat into microreservoirs in sequential fashion, avoiding the mixing of old and new sweat. Additionally, an enzyme-based reagent is embedded into the microreservoirs to quantify the glucose level in sweat by using colorimetric methods, demonstrating a high detection sensitivity at the glucose concentration from 0.1 mM to 1 mM in sweat and an excellent anti-interference performance that prevents interference from substances probably existent in sweat. In vitro and on-body experiments demonstrate the validity of the low-cost, laser-cut epidermal microfluidic patch for the chronological analysis of sweat glucose concentration and its potential application in the monitoring of human physiological information.

Crystallographic analysis and phasing of iron-assimilating protein 1 (FEA1) from Chlamydomonas reinhardtii.

As an essential component of protein cofactors, iron is important for all photosynthetic organisms. In Chlamydomonas reinhardtii, iron levels are strictly controlled by proteins such as iron-assimilating protein 1 (FEA1). This periplasmic protein is expressed under conditions of iron deficiency, but its mechanisms of function remain unknown. Because FEA1 has no amino-acid similarity to protein structures in the Protein Data Bank, its crystal structure cannot be solved by molecular replacement. Here, recombinant FEA1 protein lacking the N-terminal signal sequence was successfully purified and crystals of apo FEA1 were obtained by hanging-drop vapor diffusion. Neither selenomethionine substitution nor heavy-atom derivatization was successful; therefore, the phase problem of FEA1 crystals was solved by the native sulfur SAD method using long-wavelength X-rays (2.7 Å). Laser-cutting technology was used to increase the signal-to-noise ratio and derive an initial structure. This study will lead to further structural studies of FEA1 to understand its function and its links to the iron-assimilation pathway.

Laser‐cut I‐beam‐to‐CHS column moment‐resisting steel joints

AbstractNominated for the Professor Eduardo de Arantes e Oliveira Award at XII Conference on Steel and Composite Construction in Coimbra 2019Although open‐to‐circular hollow section (CHS) connections are highly encouraged in the current structural steelwork industry thanks to the extensive range of advantages provided by the CHS columns, a complicated and expensive fabrication procedure has limited their application in practice. The additional gusset plates or stiffeners needed to strengthen a conventional open‐to‐CHS connection lead to excessive welding quantities and localized CHS distortion, thus causing an economic as well as structural disadvantage. However, if designed efficiently, the CHS connections can offer an extensive range of solutions for modern multi‐storey structures. To that end, different types of nominally pinned and moment‐resisting “passing‐through” open‐to‐CHS connections have been developed using laser cutting technology (LCT) and proposed by the European research project LASTEICON. This current article concentrates on the LASTEICON two‐way moment‐resisting connections. The non‐linear behaviour of the connections is discussed by way of an appropriate understanding of the force transfer mechanism. Furthermore, these innovative connections are compared with directly welded conventional open‐to‐CHS connections in order to highlight the advantages offered by the “passing‐through” approach.

Characterization of moment resisting I-beam to circular hollow section column connections resorting to passing-through plates

Open-to-Circular Hollow Section (CHS) connections are highly encouraged nowadays in modern multistoried structures due to the extensive resistance provided by the CHS columns against high compression, tension as well as flexure in all directions, combined with their exceptional aesthetics. However, using more and more gusset plates or stiffeners to strengthen a conventional open-to-CHS connection causes economic disadvantage due to excessive welding quantities and substantial CHS chord yielding further limits any opportunity to exploit the full advantages offered by the open sections therefore minimizing its frequent application. However, if designed efficiently, the CHS connection can offer an extensive range of solutions which makes it an impeccable choice for the modern multi-storey structures. To that purpose, a “LASTEICON” solution is proposed in this paper investigating a “passing-through” concept, which is obtained by using laser cutting technology (LCT). Initially, a suitable moment resisting Plate-to-CHS-column connection is characterized through a detailed understanding of the relevant parameters, where the primary beams are connected at either side of the CHS column by two transverse and one longitudinal plate passing through the CHS column via laser cut slots. A detailed parametric study is conducted based on multiple Finite Element (FE) models primarily calibrated from an experimental campaign to understand the effect of each parameter and further verify and therefore establish the analytical assumptions to calculate the ultimate resistance of such connections. Finally a comprehensive design procedure is proposed to design such “passing-through” Plate-to-CHS column connections. A short comparison study is also made with the conventional (direct weld) joints to highlight the advantages offered by this LASTEICON solution.

The mass transport based on convection effects in a passive DMFC under open-circuit conditions

The study investigates the open-circuit characteristics of a passive direct methanol fuel cell (DMFC) based on temperature-induced convection effects, including the reactants distributions at anode, the non-uniform temperature distribution and the methanol crossover. A two-dimensional, well-thought-out numerical model coupling with mass transfer and momentum transfer is exploited for DMFC to investigate its inner component and temperature distributions under open-circuit condition. In addition, a 4.0 cm2 passive DMFC has been designed and manufactured by the laser-cutting technology for experimental verification. The average methanol crossover flux, methanol diffusion coefficient and crossover current are obtained, which coincide with the simulation data well. The temperature-induced convection simulation results show that the distorted temperature distribution becomes more obvious with higher methanol concentration. Furthermore, the polarization curve, cell temperature and open-circuit voltage (OCV) are measured by varying the methanol concentration to conduct more in-depth research on DMFC performance at open circuit state. The results indicate that the temperature is increased, whereas the OCV is decreased with the increase of methanol concentration, accompanied by the phenomenon of methanol crossover is aggravated. The paper provides the theory basis and the optimal operating parameters for safe start-up of DMFC.

Fabrication of laser cut I-beam-to-CHS-column steel joints with minimized welding

The available connection methods of I-beam-to-CHS-columns are complex and costly. They commonly need local stiffeners and gusset plates to allow an efficient load transfer between the beam and the column, resulting in excessive welding quantities, since directly welding the beams to the column surface increases the vulnerability of the joint to the local distortions. These problems prevent the widespread use of CHS profiles as columns in the construction sector, although they have excellent structural and architectural properties. Researchers worldwide have been investigating the possibilities to simplify the fabrication and increase the structural performance of such joints. This article proposes “LASTEICON” solution to achieve this objective: joints with “passing through” beams, obtained by using laser cutting technology (LCT). Thanks to LCT, welding quantity and fabrication time of such tubular connections can be reduced significantly, obtaining better precision with higher quality in the joint assembly, and improving the workplace safety with less manual work and more computer-programmed automation. For the development of this new joint type, the first step was to investigate the fabrication details including the tolerances required for the slots, laser cutting parameters, and welding aspects. This paper presents the whole fabrication process applied to the joints assembled with different column and beam sizes and welding types, quantifying the time and resources spent during the process. Furthermore, a detailed description of laser cutting procedure has been provided, to show its potential in the steel construction sector.

03.33: Experimental assessment of tolerances for the fabrication of laser‐cut steel joints

ABSTRACTCircular hollow sections (CHS) represent several advantages, such as uniform behaviour in all directions, possibility to obtain composite behaviour by concrete infill, hence high strength, stability and good fire resistance. Moreover, their aesthetic appeal has a great potential for the decision maker's attention, be that the architect or the building owner. However, they are not widely adopted in practice due to the complexity and high cost of their joint details. EU‐RFCS project LASTEICON (Laser Technology for Innovative Connections in Steel Construction), started on July 2016 [1] proposes simpler joint solutions with reduced fabrication costs, to be adopted between CHS columns and I beams, making use of laser cutting technology (LCT). The primary objective of the LASTEICON project is to overcome the complexity of steel joints between CHS columns and I beams, and let engineers and architects exploit the outstanding structural properties of hollow section profiles. Laser cutting will allow the reduction of the shop fabrication time, obtaining higher precision high quality joint fabrication, and improving workplace safety reducing the amount of manual labor while increasing computer‐programmed automation. This paper presents the preliminary results obtained in the Work‐Package 1 of the LASTEICON project (www.lasteicon.eu), which consisted in a study of tolerance optimization for an efficient fabrication of I‐beam‐to‐CHS column joints.

Granular rheology: measuring boundary forces with laser-cut leaf springs

In granular physics experiments, it is a persistent challenge to obtain the boundary stress measurements necessary to provide full a rheological characterization of the dynamics. Here, we describe a new technique by which the outer boundary of a 2D Couette cell both confines the granular material and provides spatially- and temporally- resolved stress measurements. This key advance is enabled by desktop laser-cutting technology, which allows us to design and cut linearly-deformable walls with a specified spring constant. By tracking the position of each segment of the wall, we measure both the normal and tangential stress throughout the experiment. This permits us to calculate the amount of shear stress provided by basal friction, and thereby determine accurate values of $\mu(I)$.

Evaluation of speed of melt evacuation in the technology of laser cutting of metals by the optical correlation method

A multichannel pyrometer was used to determine the speed of melt evacuation from an irradiated zone in laser-cutting technology with auxiliary gas. Local pulsations of brightness temperature were measured in four areas of ∼0.1 mm in diameter each spaced by 0.6 mm along the cutting front. A method is described for measuring the displacement rate of temperature heterogeneities during melt motion by mutual correlations of brightness-temperature pulsations calculated in neighboring areas. The necessity of preliminary frequency filtration of the measurement data may be due to propagation of a nonlinear wave in the melt on a metal surface under the impact of a gas jet.

LP-RLSA Design for Low-Cost Transportable BASYLIS Radar [Antenna Applications Corner

The increase in small, distributed facilities expected in the near future has raised the necessity of having low-cost, transportable radar systems. In turn, this requires the design of high-gain, low-cost, planar, robust, and easy-to-assemble antennas. In this scenario, the possibility of using a laser-cutting technology in manufacturing a linearly polarized radial-line slot array (RLSA) has been investigated. An ad hoc optimization algorithm, which takes into account the physical mechanism beyond the radial-line slot array antenna, has been developed to obtain low antenna sidelobe levels, as required by the specific BASYLIS radar application. The optimization technique allows using near-resonance radiating slots and canceling slots that are all closely spaced on the upper plate of the radial-line slot array. The measurements carried out on the antenna prototype showed very good performance, despite the use of low-cost materials and manufacturing technology.

Optimal cutting design and analysis for fault-tolerant scheme of redundant memories

Fault-tolerant design for memory production is beginning to play an important role in increasing the yield rate of manufacturing. To improve the reliability of memory manufacturing, there are many methods that have been proposed. One of the most used technologies is replacing the faulty cells with spare memory interleaved in the memory. Nowadays, laser-cutting technology improves the yield of memories because of the enhancement of the use of spare lines. However, the issue of choosing a cutting location significantly affects the utilisation of spare lines. A bad cutting location can even render it useless. To use spare lines more efficiently, this article proposes two algorithms. The first one is designed to seek out a good cutting location. It corrects some defects of previous algorithms and provides a better approach to finding cutting candidates. In addition, because most heuristic solution-finding algorithms do not work properly under the condition of cutting memory, the second algorithm, called modification of most-repair is proposed to help make the decision as to whether or not a solution exists for the faulty pattern. We can find an optimal solution by combing these two algorithms. The experimental results show that our proposed algorithms increase the reparable percentage of a 1024-by-1024 memory from 55 to 100% and also improve both the reliability of memory manufacturing and the flexibility of spare lines.

Choosing a Laser-Cutting Technology to be Applied to a Deep-Drawn Product

Residual stresses are an inevitable result of mechanical and heat treatments of steel. The stress field generated at the surface and through the cross section of a product is usually non-uniform, and there can be important stress gradients. In general residual stresses can be defined as self-balanced internal stresses existing in a free body on which no external forces are acting. In the present study the focus was on the residual stresses occurring in a steel deep-drawn product of a complex form. The residual stresses occur mainly because of different degrees of plastic deformation at different locations. The residual stresses occurring in the product as a result of the manufacturing process of deep drawing can be comparatively strong. In slitting or cutting a useful product out of a deepdrawn part by laser cutting, a portion of the residual stresses will get relieved and produce distortion of the deep-drawn product. The studies made showed that the distortion of the deep-drawn product depended on the mode of cutting-out. Also the state of the residual stresses after slitting or cuttingout of the deep-drawn product will depend on the mode of cutting-out, i.e., on the sequence of individual cuts chosen. The product used in the analysis made was a deep-drawn steel mud-guard, which makes a component part of a working machine. The various modes of cutting-out a useful product of 1260x800x370 mm in size were performed with laser cutting using cutting oxygen. The residual stresses in the mud-guard were determined with a semi-destructive hole drilling strain gage method.

Fabrication of optical elements with better than λ/1000 thickness uniformity by thin-film deposition through a multi-aperture mask

A technique is presented for sub-nanometre correction of precision-polished optical surfaces. The technique uses thin metallic masks with multiple apertures of varying widths to selectively occlude a beam of depositing species in an ion beam sputtering system. The masks are designed directly from measured surface profile maps of the optical surface, and are fabricated using well-established laser-cutting technology commonly used to fabricate solder masks for the semiconductor industry. The selective deposition has proved highly effective for fabrication of large-aperture Fabry–Perot filters and has resulted in optical uniformities of less then 0.3 nm rms over a clear aperture of 37.5 mm. This manuscript will give details of the mask design, deposition technique, and results from recent surface correction runs.

Measurement of acoustic emission and deformations in laser cutting of deep-drawn sheet parts

The paper treats the results obtained in simultaneous measurements of Acoustic Emission (AE) with PZT AE sensors and of deformations with resistance measuring rosettes carried out during and immediately after laser cutting-out of a deep-drawn sheet product, i.e., mudguard. A goal of the study presented in this paper was primarily to analyse the sources of AE present during and immediately after laser cutting. It was found that the main source of AE during laser cutting was the cutting gas jet. The 'true' AE occurring during the laser-cutting process and immediately after cutting of the mudguard is related to the release of the residual stresses present in the deep-drawn sheet product and to the processes in material generated by the absorbed laser light. The energy of the AE signals recorded during the cutting process and immediately after cutting, the number of AE hits detected by individual sensor in a unit of time and their cumulative value indicate a connection with the phenomena in the material which may after further investigation enable optimisation of the laser-cutting technology, including the selection of the cutting conditions.