Search results for "Forming"
showing 10 items of 1719 documents
Reconstruction of the Rib Vaults of the Hypostyle Hall in the Maniace Castle of Siracusa After the 1693 Earthquake
2016
ABSTRACTBuilt in the first half of the 13th century on behalf of the Emperor Frederick II, the Maniace Castle of Siracusa focuses its enigma in the hypostyle hall (which was composed of 25 quadripartite rib vaults) and the design criteria adopted for its implementation. Recent research and a careful rereading of the documentary “restoration project” after the earthquake of 1693 have offered new tools to understand the construction techniques and building procedures for the entire organism. It has been possible to demonstrate that the different material (white limestone and volcanic stone) used for the vaults is, in fact, a product of reconstruction. The constructive node, which historiograp…
The Bell-Tower Facade: An Aseismic Device in Sicily Between the 12th and 18th Centuries
2014
Imposing tower facades with belfries in the last order were built in Sicily Italy, from the Middle Ages to the late Baroque period. Until the 16th century, this model, which was inspired by northern European examples, also had a parallelepiped forepart leaning against the facade, working as containment for the pressure imparted by the inner longitudinal arches on the front, and amplified in case of earthquakes. The lacking static efficiency of these early structures is demonstrated by collapses during the strong earthquakes that hit the island in the modern age. Despite numerous cases of destruction, the memory of some prototypes survived in Sicilian constructive memory through the elaborat…
New Architectural Models and Building Tradition: A Dialogue in Early Modern Sardinia - The Jesuit Church in Sassari
2014
L'architettura nella Sardegna di età moderna è caratterizzata da una forte continuità con pratiche antecedenti. Nella seconda metà del XVI secolo, nuovi modelli, legati in particolare alle nuove tendenze nel campo dell'architettura militare e il classicismo della controriforma cattolica, affiancano la tradizione costruttiva gotica.La chiesa dei Gesuiti di Sassari offre un interessante esempio di intreccio tra queste modalità architettoniche, causato da un improvviso cambio alla guida del cantiere. Giovan Maria Bernardoni, un architetto gesuita italiano, redasse il progetto iniziale della chiesa sul modello del Gesù di Roma, ed essa fu parzialmente costruita sotto la sua direzione. Dopo la s…
Assessment of textile craft products’ creativity in the Latvian competition for pupils
2018
The purpose of the research is to explore the results of pupils’ creative activity in a competition in textile craft in Latvia and to find trends in the creation of textile craft products. The applied method is the analysis of creative work items made by pupils from Forms 6–7 (N1 = 106) and Forms 8–9 (N2 = 132): photos, designs and textile craft products. Among the hand and foot garments, the most popular products in both age groups were fingerless gloves. The knitting technique was used most frequently, and most of the items were wearable. Creativity predominantly manifested in the combinations of colours, techniques and materials, followed by creative technology solutions and creative pro…
Design of complex sheet metal forming processes: a new computer aided progressive approach
2010
The growing interest in sheet metal stamping processes, particularly in automotive industry, led to three main issues in this field: request of very complex shapes; growing interest in springback control; solution of multi-objective problems. This makes the design of the sheet metal stamping processes very difficult, since the number of both design variables and design objectives are progressively increased; therefore, proper design methodologies to reduce times and costs are highly required. In this paper, an innovative design approach able to manage and optimize complex stamping operations is proposed. In particular, a progressive design approach based on the integration between numerical…
Shape Distortion and Thickness Distribution during SPIF Processes: Expermental and Numerical Analysis
2011
Single Point Incremental Forming (SPIF) is a quite new sheet forming process which offers the possibility to deform complex parts without dedicated dies using only a single point tool and a standard 3-axis CNC machine. The process mechanics enables strains much higher than traditional sheet forming processes, but particular attention must be given to the final part geometrical accuracy. In this paper the capabilities of a dedicated explicit numerical model are quantitatively analyzed on pyramid-shaped parts. In particular a comparison between experimental and numerical results is reported. Three different shapes at the varying of the stamping angle were considered and the final shape was ac…
Optimal Blankholder Force Path in Sheet Metal Forming Processes: An Al Based Procedure
1999
Abstract Blankholder force plays a fundamental role in the deep drawing process mechanics since it controls, by friction, the material flow into the die cavity. The availability of computer controlled hydraulic presses in the industries promoted a new research field focused on the definition of optimal BHF histories, function of the punch displacement; such studies were aimed to the determination of the so called “process window”, i.e. the BHF path which permits to obtain the maximum height sound component avoiding both wrinkling and tearing. In the paper a design procedure is proposed in order to determine the optimal BHF path in an axisymmetric deep drawing process: in particular, a close…
Developing a Knowledge Base about the Technological Forces within the Asymmetric Incremental Forming Process
2015
Asymmetric single point incremental forming (ASPIF) has been recognized as a solution with potential in manufacturing small batches or single sheet metal parts. The approach presented in this paper presents the development of a knowledge base regarding the values of the technological force within the ASPIF process and the influence of some technological parameters such as feed, speed of the punch, thickness of the part and step, upon them. The method is based on the use of the information provided by the CNC machine sensors. Relationships between the torques developed by the drive motors on each axes and the technological forces will be set in order to refine the raw information displayed o…
Shape and dimensional accuracy in Single Point Incremental Forming: State of the art and future trends
2007
Abstract The paper is aimed to discuss some relevant issues concerning an innovative sheet metal forming technology, namely Single Point Incremental Forming. The advantages of this technology are addressed, including its capability to provide effective answers to some impellent industrial requirements: process flexibility, strong customer orientation, production of highly differentiated goods at low industrial costs. As well some relevant drawbacks are highlighted, mainly as concerns the level of accuracy permitted by the process. A wide recognition of the research efforts in this field is presented, taking into account some general considerations on the difference sources of shape and dime…
Analysis of Energy Efficiency of Different Setups Able to Perform Single Point Incremental Forming (SPIF) Processes
2014
Abstract Production processes, as used for discrete part manufacturing, are responsible for a substantial part of the environmental impact of products, but are still poorly documented in terms of environmental impact. The present paper proposes an energy analysis of single point incremental forming processes (SPIF). The electrical energy consumption of two different setups have been considered and compared. In particular the power demand of one of the most used machine tools architecture able to perform SPIF process, namely a CNC milling machine, has been measured. The obtained results have been compared with the ones obtained for an innovative high speed incremental forming processes perfo…