Blank Dimensions Research Articles

The Square cup deep drawing: Technology transfer from experts to increase production in small and medium enterprise (SME) groups

The deep drawing is a complex steel forming method involving blank dimensions, dimension/height ratio (D/H ratio), and clearance between die and punch (D/P allowance). Failure to identify proper blank dimensions and D/H ratio can lead to production defects such as tears, while failure to recognize the correct clearance can cause wrinkles. This article discusses technology dissemination to Small and medium-sized enterprises (SMEs) for the deep drawing process in producing R-ornament components #3D40x40, considering these crucial parameters. R-ornament #3D40x40 was manufactured using SPCC-SD material with a thickness of 0.65 mm. The Participatory Action Research (PAR) method was employed to collaboratively optimize blank dimensions, D/H ratio, and dies/punch (D/P) allowance with partners. The optimization of blank dimensions successfully eliminated the need for the trimming process, resulting in reduced investment costs in dies and die setup by IDR 15 million and 2.16 million, respectively. Identifying a D/H ratio of 1.32 successfully eliminated tear defects and determining a D/P allowance of 0.87 mm on each side eradicated wrinkle defects in the product. This article contributes to Goal 9 of the Sustainable Development Goals (SDGs), specifically focusing on the Small and Medium-sized Enterprises (SMEs) sector.

Technological Process Stability Assessment Based on the Results of Weapon Barrel Blank Dimension Control

The technological process of barrel manufacturing begins with the operation of stitching the rods to create a channel in the workpiece. Due to the effect of significant mechanical loads on the workpiece, inhomogeneities occur in cross-section in the form of deviations in diameter. To ensure the stability of the process, it is necessary to analyze the quality indicators in the manufacture of blanks. Product quality improvement consists in the continuous improvement of technological processes, the evaluation criteria of which are quality indicators, for example, according to the geometric dimensions of products. The company gains competitive advantage when the indicators remain stable over time and meet all the stated requirements in the regulatory documentation. process stability is defined as an indicator that ensures the constancy of the probability distributive law of its parameters for a certain period of time. Currently, there is no quality indicator of products or services that have absolute stability. The variability of the indicator is influenced by a fairly wide range of different indicators: the difference in the mechanical characteristics of the source material and workpieces, the wear of technical equipment (fixtures, equipment, tools), changes in environmental conditions, the level of qualification of working personnel, etc. Depending on the degree of influence of these factors, there will be instability in the values of quality indicators. To determine the reasons for the quality indicator spreading, studies were conducted on the example of blanks of rifle barrels. In the course of the study, the method of Shuhart control charts was used to determine the causes of deviations unambiguously. This method made it possible to construct a time schedule for changing the parameters of the process of obtaining barrel blanks before forging to carry out statistical control of its stability. The values of the critical geometric dimensions of the barrel blanks before forging were measured. Deviations of the obtained values from the required parameters were found, which indicates a violation and instability of the process of manufacturing the barrel blanks.

Wall thickness control in multi-stage hydroforming of multiwave seal ring with small diameter

Thinning rate is a crucial factor in forming quality of the thin-walled seal ring with complex features. To control the excessive thinning by altering the stress state during the material deformation, a new multi-stage three-dimensional (3D) hydroforming technology was proposed in this work. Based on the characteristics of the seal ring and the used superalloy strip, a multi-stage internal pressure forming process was established through finite element analysis (FEA) and forming experiment verification. In addition, the distribution of wall thickness in every stage was discussed. And the influence of the width of deformation zone and the pressure loading path in the cavity on the wall thickness of the part in each step was studied. Finally, the optimal forming parameters of each step that can achieve a stable state of metal flow were obtained. The experimental results demonstrated that the developed 3D hydroforming technology can accurately control the material flow in the multi-stage forming of the multi-wave seal ring with small-diameter and ultrathin wall thickness. For the optimized parameter combination, the blank dimensions of deformation zone are 8 mm in the first step and 18 mm in the second step, while the pre-bulging pressure is 9 ~ 12 MPa and the maximum pressure is 100 MPa in the two steps.

Energy-Saving and Low-Carbon Gear Blank Dimension Design Based on Business Compass

Sustainable blank dimension design is the key to the implementation of green industrial development. However, blank dimension design only considers the blank production factor of the blank dimension design stage, which cannot guarantee the blank production stage and the use stage’s overall goal. In this paper, based on the guiding thinking of a business compass, a low-carbon and low-energy consumption blank dimension optimization design model was proposed. Taking the process parameters of the production and the use of the blank as the variables, the grey wolf optimization algorithm was adopted to solve the problem. Taking the gear blanks dimension as an example, the optimized blank dimension is 98.6, compared with the standard blank dimension of 100, 105, the energy consumption is 95.7% and 93.1%, the carbon emission is 92.6% and 90.2%, and the material consumption is 96.5% and 87.5%, respectively. The sustainable blank dimension design has obvious advantages in terms of low energy consumption and low carbon, and it can save a lot of materials; it can also promote product sustainability.

Optimum Design of Square Blank Dimension with Low Energy Consumption and Low Cost for Milling Based on Business Compass Concept

Blank is the foundation for manufacturing enterprise production. The change of blank dimension is the fundamental purpose of product processing, and blank dimension change process dramatically affects the cost and energy consumption of blank production and use process. Therefore, the blank dimension design is of great significance for the sustainable development of enterprises. Based on the management concept of the business compass, combined with the enterprise development plan and production situation, this article established a blank dimension optimization design model, which can design the blank dimension according to enterprise demand. The model took the energy consumption and cost of the blank production and used process as the optimization objectives, and was solved by the gray wolf algorithm. The model was verified by analyzing the machining process of a fixture cavity. By comparison with standard square blank dimensions, the research results showed that the optimized square blank dimension can meet the objective of saving energy and reducing costs, it can also fully coordinate economy and resource consumption.

Formability Experiments for Unidirectional Thermoplastic Composites

Reliable composite forming experiments are required to characterize composite formability, to aid material development, and to validate process simulations models. Due to practical reasons, however, typically a limited amount of forming configurations is studied. The objective of this study is, therefore, to develop a methodology for obtaining controlled forming results in a wide range of configurations. Press forming experiments using a dome geometry were used to explore the formability of two commercial unidirectional thermoplastic composite materials. A variety of forming configurations was employed by changing the blank dimensions and layup. The observation of wrinkling defects was simplified by leaving an additional 3 mm tool gap. Blank width and layup had the most influence on the wrinkling severity, followed by blank thickness and length. Quasi-isotropic layups were found to produce wrinkles in nearly all cases, confirming a difficulty in general to form double curved parts. The size and number of wrinkles in these layups were found to change with the stacking sequence. Cross-ply layups showed better formability, but significant wrinkles were still observed depending on the orientation of the blank relative to the layup. The formability experiments using a dome geometry provided a reliable methodology for controlled forming results in many configurations using a generic toolset. Additionally, a comprehensive comparison of formability for two commercial thermoplastic UD materials in a variety of scenarios was provided.

A Versatile Punch Stroke Correction Model for Trial V-Bending of Sheet Metals Based on Data-Driven Method.

During air bending of sheet metals, the correction of punch stroke for springback control is always implemented through repeated trial bending until achieving the forming accuracy of bending parts. In this study, a modelling method for correction of punch stroke is presented for guiding trial bending based on a data-driven technique. Firstly, the big data for the model are mainly generated from a large number of finite element simulations, considering many variables, e.g., material parameters, dimensions of V-dies and blanks, and processing parameters. Based on the big data, two punch stroke correction models are developed via neural network and dimensional analysis, respectively. The analytic comparison shows that the neural network model is more suitable for guiding trial bending of sheet metals than the dimensional analysis model, which has mechanical significance. The actual trial bending tests prove that the neural-network-based punch stroke correction model presents great versatility and accuracy in the guidance of trial bending, leading to a reduction in the number of trial bends and an improvement in the production efficiency of air bending.

Optimum Design of Blank Dimensions Guided by a Business Compass in the Machining Process

Blanks, an important raw material for the manufacturing industry, are semi-finished products for further processing. The energy consumption and processing efficiency in the process of blank production and use can be determined to a great extent in the blank design stage. The design of appropriate blank dimensions is an important means of realizing ecological civilization. Current blank designs seldom consider the production conditions of enterprises. In order to design energy-saving and efficient blanks on the basis of the actual conditions of an enterprise, this paper establishes the blank dimension optimization design model from the perspective of a business compass. With energy savings and efficiency as the goals, and the blank production and use-process equipment parameters as variables, the blank dimensions were optimized by an NSGA-II algorithm, and the results showed that the energy efficiency and processing efficiency of the designed blank dimensions were significantly better than for the existing blank dimensions in the process of enterprise operation.

Simulation of the micro Single Point Incremental forming process of very thin sheets

The purpose of this paper is to simulate a complex forming process with parameters identified from tensile and shear tests. An elastic-plastic model is retained which combines a Hill’s 1948 anisotropic criterion and plastic potential using a non-associated flow rule. Firstly, a mechanical characterization is made with homogenous tests like tensile and shear tests [1]. On the other hand a process of micro Single Point Incremental forming is simulated [2]. It consists in deforming a clamped blank using a hemispherical punch which has a small diameter compared to the blank dimensions. From a small-size sheet of 0.2 mm thick, a square-based pyramid is obtained incrementally, with a define height path and advanced speed, by a tool instrumented to measure the forming force, which deforms locally the material. It is shown that the non-associated flow plasticity model leads to a good agreement between experimental and numerical results for the evolution of the punch force during the process.

Features of Use of Rapid Prototyping Technology in the Manufacture of Wax Models of GTE Turbine Blades

The paper presents the main results related to the peculiarities of using 3D printing technology and methods of rapid prototyping in the manufacture of wax models of blades of a GTE turbine. The main design solutions that must be used in the design of a blade blank are presented in detail: the total shrinkage coefficient, equidistant rolling of the airfoil profile, allowance along tract surfaces, radial fillets, and a number of others. The results of control of geometric dimensions of the turbine blade blanks at the corresponding stages of the technological process showed deviations from the nominal value within the tolerance range for the executable dimensions, and the statistical information from the measurement of an experimental batch of wax models of blade blanks showed stability of the silicone tooling and ability to manufacture a series of wax models of the blades in the amount of 100 pieces when using one mold.

Numerical Optimization of the Blank Dimensions in Tube Hydroforming Using Line-Search and Bisection Methods.

The change from a consolidated manufacturing practice to a new solution is often a complex problem because of the operative limits of technologies and the strict constraints of industrial parts. Moreover, the new process must reflect or enhance the characteristics of the product and, overall, it must be more competitive in performances and costs. Accordingly, the development of a new process is a multilevel and multivariate problem that requires a systematic and hierarchical approach. The present paper focuses on the development of a Tube Hydroforming process capable to replace the current practice for production of T-Joint parts made of AISI 316L for the water pipes market. In particular, the problem must withstand many process and product constraints. Therefore, it was split in three steps focused on specific aspects of the process: identification of process parameters and configuration, numerical optimization of the blank tube dimensions (length and thickness), experimental tests and final improvements. In particular, two numerical methods were implemented in the optimization step: the line–search method to approach to the optimum point and Bisection method to refine the search. These approaches allowed us to identify the optimum process configuration and, in particular, the optimal dimensions of the blank tube that allows one to achieve the product requirements with the minimum cost of material.

Energy Saving and Low-Cost-Oriented Design Processes of Blank’s Dimensions Based on Multi-Objective Optimization Model

The blank’s dimensions are an important focus of blank design as they largely determine the energy consumption and cost of manufacturing and further processing the blank. To achieve energy saving and low cost during the optimization of blank dimensions design, we established energy consumption and cost objectives in the manufacturing and further processing of blanks by optimizing the parameters. As objectives, we selected the blank’s production and further processing parameters as optimization variables to minimize energy consumption and cost, then set up a multi-objective optimization model. The optimal blank dimension was back calculated using the parameters of the minimum processing energy consumption and minimum cost state, and the model was optimized using the non-dominated genetic algorithm-II (NSGA-II). The effect of designing blank dimension in saving energy and costs is obvious compared with the existing methods.

Проблемы технологического обеспечения точности массы изделий

Mathematical dependences for the rated definition of the mass error of parts and a product as a whole in correlation with tolerances for dimensions of blanks and machinery and also with parameters of roughness and waviness of their surfaces are offered. The algorithms for technological support of the accuracy required for a mass of parts and a product as a whole are developed.

Structure and Anisotropy of the Mechanical Properties of Hot- and Cold-Rolled Semi-Finished Products from Aluminium-Lithium Alloys

Research of structure and anisotropy of the mechanical properties of hot-and cold-rolled semi-finished products from Al-Mg-Li (1420 and 1424) and Al-Cu-Li (V-1461) alloys was conducted. Semi-finished products were made in industrial conditions by standard technologies. During the tension test ultimate strength, yield stress, elongation and coefficients of lateral strain in three directions (at 0°, 45° and 90° angles to the rolling direction) were determined in order to study the planar anisotropy. It was established that the main characteristic inherent to both the first generation of aluminium-lithium alloys (1420) and the subsequent ones (1424, V-1461) is a pronounced anisotropy of the mechanical properties including the characteristics of plastic strain. At the same time, as for most aluminium alloys, aluminium-lithium alloys are characterized by low values of the lateral strain coefficients. It leads to a number of negative consequences in the subsequent forming: distortion and dimensions alteration of parts, limitation of formability, metal losses due to overestimation of thickness and dimensions of blanks, weight increase of the construction.

Reduction intensity of backed blades: Blank consumption, regularity and efficiency at the early Neolithic site of Boncuklu, Turkey

Estimating the extent of reduction intensity on lithic artefacts has become a key goal of lithic analyses in recent decades. An understanding of a core or tool's reduction intensity can lead to intra- and inter-site interpretations regarding patterns of human behaviour. Decades of research on this topic have led to a diverse suite of quantifiable measures of reduction encompassing almost all artefact types. We present and test the efficacy of a new method for measuring reduction intensity for backed blades, one of the few remaining artefact types lacking a reliable measure of reduction. As instances of successive retouching of backed blades are rarely documented, we use this reduction intensity metric to estimate original blank size, rather than model multiple stages of reduction. Allometric relationships of blade thickness to length and width were used to estimate original microlith blank size, thereby offering a quantification of reduction intensity. This method was then applied to the microliths, a specific type of small backed blade, from the early Neolithic site of Boncuklu, Turkey. Reconstructing the original mass and dimensions of microlith blanks allows inferences to be made regarding the regularity, efficiency and decision making involved in microlith production. These microliths were produced using similarly sized blanks that were selectively and nearly completely consumed in this reduction sequence. This aspect of lithic technology at Boncuklu involved little waste and therefore enabled the inhabitants to cope with the constraints of raw material access and negotiate the changes to subsistence and social organisation occurring at the beginning of the Neolithic. While we test the efficacy of this new method on the Neolithic of Turkey, it could equally be applied to any blade- or bladelet-based backed artefact industry. These industries existed at various times in Europe, the Near East, Africa, South Asia, and parts of Australia, together spanning the Middle Stone Age, Later Stone Age/Upper Palaeolithic, Epipalaeolithic, Mesolithic and Neolithic.

Mathematical modeling of processes of heat and mass transfer during drying of wood biomass

For the first time, a mathematical model for the drying of woody biomass during conductive heating with localization of the evaporation front has been formulated. The processes of moisture removal during the filtration of steam through the porous structure of the material at an ambient temperature of Te = 373 K were considered. Humidity was varied (in the range from 6% to 40%) and dimensions of wood blanks (Rd = 0.0035 - 0.035 m). Based on the results of numerical simulation, the conditions and characteristics (evaporation rate Wisp, drying time τ dry) of the process of moisture removal from wood biomass are determined. The mathematical model allows to calculate the drying time, as well as the mass evaporation rate for different sizes of wood sample, humidity and temperature conditions.

Numerical and Experimental Study on Manufacture of a Novel High-Capacity Engine Oil Pan Subjected to Hydro-Mechanical Deep Drawing

The oil pan is equipped at the bottom of engine crankcase of the automobile to prevent impurity and collect the lubrication oil from the surfaces of the engine which is helpful for heat dissipation and oxidation prevention. The present study aims at manufacturing a novel high-capacity engine oil pan, which is considered as a complex shaped component with features of thin wall, large size and asymmetric deep cavity through both numerical and experimental methods. The result indicated that it is difficult to form the current part through the common deep drawing process. Accordingly, the hydro-mechanical deep drawing technology was conducted, which consisted of two steps, previous local drawing and the final integral deep drawing with hydraulic pressure. The finite element analysis (FEA) was carried out to investigate the influence of initial blank dimension and the key process parameters such as loading path, draw-bead force and fillet radius on the formability of the sheet blank. Compared with the common deep drawing, the limit drawing ratio by hydro-mechanical deep drawing can be increased from 2.34 to 2.77, while the reduction in blank wall thickness can be controlled in the range of 28%. The formability is greatly improved without any defects such as crack and wrinkle by means of parameters optimisation. The results gained from simulation keep a reasonable agreement with that obtained from experiment trials.

Soft measurement model of ring’s dimensions for vertical hot ring rolling process using neural networks optimized by genetic algorithm

Vertical hot ring rolling (VHRR) process has the characteristics of nonlinearity, time-variation and being susceptible to disturbance. Furthermore, the ring’s growth is quite fast within a short time, and the rolled ring’s position is asymmetrical. All of these cause that the ring’s dimensions cannot be measured directly. Through analyzing the relationships among the dimensions of ring blanks, the positions of rolls and the ring’s inner and outer diameter, the soft measurement model of ring’s dimensions is established based on the radial basis function neural network (RBFNN). A mass of data samples are obtained from VHRR finite element (FE) simulations to train and test the soft measurement NN model, and the model’s structure parameters are deduced and optimized by genetic algorithm (GA). Finally, the soft measurement system of ring’s dimensions is established and validated by the VHRR experiments. The ring’s dimensions were measured artificially and calculated by the soft measurement NN model. The results show that the calculation values of GA-RBFNN model are close to the artificial measurement data. In addition, the calculation accuracy of GA-RBFNN model is higher than that of RBFNN model. The research results suggest that the soft measurement NN model has high precision and flexibility. The research can provide practical methods and theoretical guidance for the accurate measurement of VHRR process.

The Refinement Algorithm of Blank Outline Based on One-Step Inverse Analysis

Blank dimensions and outlines can be obtained in one-step inverse analysis. Applying more accurate mesh will achieve more precise outlines while usually lead to the increase of computation time. To ensure operation efficiency, this paper proposes a new blank outline refinement algorithm based on one-step inverse analysis. Firstly, the initial configuration is obtained from the final configuration by one-step inverse analysis. Secondly, all outline nodes is projected to the nearest element in the final configuration. Thirdly, according to the position of projected nodes in the element, the coordinate of outline nodes in the initial configuration is achieved through mapping. Finally the number of outline nodes is increased in rounded corners, the coordinate of added nodes are calculated through interpolation. At last all outlines corresponding to characteristic lines of part surface are acquired. Using A-pillar as an example, outlines are calculated by the refinement algorithm and commercial software. It proves that under the same mesh quality, outlines obtained by refinement algorithm become more accurate and smooth, especially in rounded corner. The results can contribute to judge the rationality of blank shape and improve the final part forming property. This algorithm refines the accuracy of outlines and ensures the efficiency of one-step inverse analysis.

An ethnographic experiment of endscraper curation rate among hadiya hideworkers, ethiopia

The extent of reduction in retouched stones serves as a proxy for curation. In the archaeological record, reduction intensity must be inferred from discarded remnants of tools. The contemporary use of scraper blades by hideworkers in southern Ethiopia provides archaeologists rare opportunities where original tool dimensions can be directly measured and other variables investigated. This study closely examines previously suggested factors for inter-group variability in the degree of hidescraper curation amongst the Hadiya. Potential sources of variability are controlled for through the provision of experimental blanks to groups associated with different raw material access and costs. Results strengthen previous conclusions that differential raw material cost significantly affects scraper curation rates. However, whether original blank size represents a major source of such variability could not be discerned, as the group with higher raw material costs did not exploit higher potential utility from experimental blanks. Age-old traditions of specific raw material procurement and blank dimensions seem to represent another source of variability in scraper curation rates. The potential effect of passive style on tool use patterns in archaeological assemblages is difficult to identify, albeit important to consider.