@article{
	11589_3222,
	author = { Spekowius M  and  Spina R  and  Hopmann C },
	title = {Mesoscale simulation of the solidification process in injection moulded parts},
	year = {9999},
	journal = {JOURNAL OF POLYMER ENGINEERING}
}
@conference{
	11589_23704,
	author = { Spekowius M  and  Spina R  and  Laschet G  and  Hopmann C },
	title = {Simulation of inhomogeneous material properties in injection moulded parts},
	year = {2015},
	booktitle = {3rd ECCOMAS Young Investigators Conference & 6th GACM Colloquium}
}
@conference{
	11589_20247,
	author = { Spekowius M  and  Spina R  and  Laschet G },
	title = {Towards a precise simulation of effective material properties in injection moulded parts taking into account inhomogeneous microstructures},
	year = {2015},
	booktitle = {2nd International Injection Moulding Conference}
}
@conference{
	11589_18451,
	author = { Spekowius M  and  Schirrmann C  and  Spina R  and  Hopmann C },
	title = {A new method for the calculation of the spherulite growth in solidifying semi-crystalline polymer},
	year = {2015},
	booktitle = {SPE ANTEC}
}
@conference{
	11589_18403,
	author = { Spina R},
	title = {Foam Injection Moulding of PE/EVA blends},
	year = {2015},
	booktitle = {XII Convegno dell’Associazione Italiana di Tecnologia Meccanica (A.I.TE.M.)}
}
@conference{
	11589_22783,
	author = { Laschet G  and  Hul P  and  Spekowius M  and  Hopmann C  and  Spina R },
	title = {Two-Level Homogenization of 3D Polypropylene Microstructures of an Injection Moulded Component},
	year = {2015},
	booktitle = {4th International Conference on Material Modeling}
}
@conference{
	11589_18450,
	author = { Spina R},
	title = {Foam Injection Moulding of PE/EVA blends with an azodicarbonamide agent},
	year = {2015},
	journal = {KEY ENGINEERING MATERIALS},
	volume = {651-653},
	booktitle = {Material Forming ESAFORM 2015},
	pages = {863--868}
}
@article{
	11589_5511,
	author = { Spina R},
	title = {Technological characterization of PE/EVA blends for foam injection molding},
	year = {2015},
	journal = {MATERIALS & DESIGN},
	volume = {84},
	abstract = {Foam injection molding is one of the most important processes for producing lightweight plastic parts. The main feature of this process is the use of a foam blowing agent (physical or chemical) that decomposes during heating, generating gasses that are dispersed into the melt. Predicting the microstructure of the final part requires the investigation of the foam process which is a complex problem because it is necessary to combine transport phenomena of the multi-phase flow in non-isothermal conditions with foam kinetics and gas formation. The aim of this work is to evaluate the material-processing relationship in foam injection molding. The experimental measurements of PE/EVA blends, properly formulated, coupled to two types of ADC foaming agents were carried out using differential scanning calorimetry and rotational rheometry. The injection molding and direct measurements of foamed parts were then performed, based on previous measurements, to evaluate the process performance.},
	doi = {10.1016/j.matdes.2015.06.128},	
	pages = {64--71}
}
@article{
	11589_1273,
	author = { Spina R  and  Spekowius M  and  Hopmann C },
	title = {Multi-scale thermal simulation of polymer crystallization.},
	year = {2015},
	journal = {INTERNATIONAL JOURNAL OF MATERIAL FORMING},
	volume = {8},
	abstract = {Crystallization from polymer melt is one of the most fundamental phenomena of material phase transformations. The possibility of controlling crystallization kinetics is essential to achieve the proper polymer microstructure and consequently obtain the desired material properties. The main objective of the presented work is to compute crystallization kinetics of semicrystalline thermoplastics in an injection molding process with multi-scale modeling. This is done by identifying the analytical parameters needed to connect crystallization kinetics with molecular material properties and applying the analytical scheme to the numerical simulation during cooling. The numerical method, crystallization kinetics and their implementation into numerical software are described as well as the experimental data.},
	doi = {10.1007/s12289-014-1169-8},	
	pages = {497--504}
}
@conference{
	11589_23703,
	author = { Spina R  and  Spekowius M  and  Hopmann C },
	title = {Plastic processing technology from macro to micro: application to injection moulding},
	year = {2014},
	booktitle = {Proceeding of SCORE@POLIBA Workshop}
}
@conference{
	11589_18452,
	author = { Spekowius M  and  Spina R  and  Laschet G  and  Hopmann C },
	title = {Multiscale simulation of semi-crystalline thermoplastics in the injection moulding process},
	year = {2014},
	booktitle = {11th World Congress on Computational Mechanics (WCCM 2014)}
}
@article{
	11589_3687,
	author = { Spina R  and  Spekowius M  and  Dahlmann R  and  Hopmann C },
	title = {Analysis of polymer crystallization and residual stresses in injection molded parts},
	year = {2014},
	journal = {INTERNATIONAL JOURNAL OF PRECISION ENGINEERING AND MANUFACTURING},
	volume = {15},
	pages = {89--96}
}
@article{
	11589_5733,
	author = { Spekowius M  and  Spina R  and  Hopman Ch },
	title = {Berechnung der Gefügestruktur},
	year = {2014},
	journal = {KONSTRUKTION},
	volume = {11/12},
	abstract = {Teilkristalline Thermoplaste sind eine wichtige Werkstoffgruppe der thermoplastischen Kunststoffe. Im Gegensatz zu rein amorphen Kunststoffen kommt es bei der Erstarrung dieser Materialien zu einer periodischen Anordnung der Molekülketten. Dies kann beispielsweise durch eine wiederholte Faltung der Ketten geschehen, wodurch dicht gepackte, geordnete Bereiche entstehen. Es gibt dabei einige limitierende Faktoren, die die vollständige Erstarrung der Polymerschmelze in periodischen Anordnungen verhindern. Neben Schwankungen des Molekulargewichtes sind hier beispielsweise auch Verschlaufungen der Polymerketten zu nennen. Folglich existieren neben den kristallinen auch amorphe Bereiche mit gleichen chemischen, aber unterschiedlichen physikalischen Eigenschaften. Man spricht daher auch von teilkristallinen Werkstoffen und gibt den Anteil der kristallinen Bereiche mit dem Kristallisationsgrad an. Durch die Faltung der Polymerketten entstehen plattenförmige Anordnungen der Moleküle, Lamellen genannt, die charakteristisch für die meisten teilkristallinen Thermoplaste sind. Die Lamellen können in der erstarrten Schmelze in unterschiedlichen Konfigurationen zu Überstrukturen angeordnet sein, wie beispielsweise in einer radialen oder im Falle einer hochorientierten Schmelze in einer Shish-Kebab Anordnung. Die radiale Struktur, auch Sphärolith ge- nannt, ist dabei die bekannteste Struktur, weil sie bei vielen teilkristallinen Werkstoffen, insbesondere den Massen- kunststoffen PP und PE auftritt. Die Sphärolithe können dabei Durchmesser von wenigen Mikrometern bis zu einigen Millimetern haben (Bild 1). Eines der Forschungsziele am IKV ist es, eine Gefügestruktur bis zu einer Größenordnung von wenigen μm für spritzgegossene Bauteile zu berechnen.}
}
@inbook{
	11589_14846,
	author = { Hopmann C  and  Gorzelitz V  and  Spekowius M  and  Spina R  and  Borchmann N },
	title = {Considering internal properties in part design},
	year = {2014},
	publisher = {Spinger-Verlag},
	address = {BERLIN},
	booktitle = {International Colloquium Plastic Technology}
}
@conference{
	11589_18199,
	author = { Spina R  and  Spekowius M  and  Hopmann C },
	title = {Analysis of polymer crystallization with a multiscale modeling approach},
	year = {2014},
	journal = {KEY ENGINEERING MATERIALS},
	volume = {611-612},
	booktitle = {Key Engineering Materials},
	abstract = {The main objective of the presented work is to describe the crystallization kinetics of semi-crystalline thermoplastics with a multiscale model implemented into the COMSOL software and the in-house developed code SphäroSim. The filling and cooling simulations, implemented by using the computational fluid dynamics (CFD) and heat transfer (HT) modules of COMSOL, require the simultaneous solution of non-Newtonian multi-phase flow (polymer/air) and thermal fields in non-isothermal condition and transient regime. The simulation results are collected, converted into the OpenSource file format VTK (Visualization Toolkit) and transferred to the SphäroSim code after a matching operation with the COMSOL mesh. The SphäroSim code uses COMSOL results as input data to compute crystallization kinetics, using the COMSOL data as boundary conditions in the microstructure simulation. This allows the time resolved calculation of the crystallization process and a prediction of the final microstructure in the part which can be used in further simulations such as a structural analysis. The analytical parameters needed to connect crystallization kinetics with molecular material properties and applying the analytical scheme to the numerical simulation during filling and cooling in an injection moulding process are identified.},
	pages = {928--936}
}
@conference{
	11589_20249,
	author = { Ancona F  and  De finis R  and  Galietti U  and  Guglielmi P  and  Palumbo D  and  Palumbo G  and  Piccininni A  and  Piglionico V  and  Sorgente D  and  Spina R  and  Tricarico L },
	title = {Development of advanced materials and innovative technologies for the manufacturing of turbo machines to be used in very hard working conditions: Characterization of stainless steels for Oil &Gas applications.},
	year = {2014},
	booktitle = {Proceeding of SCORE@POLIBA Workshop}
}
@article{
	11589_8042,
	author = { Sorgente D  and  Carbonara A  and  Colonna P  and  Palumbo G  and  Spina R  and  Brivio R  and  Tricarico L },
	title = {Simulazione numerica del processo di formatura superplastica di un componente complesso},
	year = {2014},
	journal = {LAMIERA},
	volume = {6},
	abstract = {AFFRONTIAMO LA CARATTERIZZAZIONE DI UN LEGA DI ALLUMINIO FINALIZZATA ALLA CREAZIONE DI
UN MODELLO NUMERICO DI UN PROCESSO DI FORMATURA SUPERPLASTICA. L’INDIVIDUAZIONE DEI
PARAMETRI DEFORMATIVI OTTIMALI E DELL’EQUAZIONE COSTITUTIVA DEL MATERIALE HANNO PERMESSO
DI ANALIZZARE LE CRITICITÀ DI PROCESSO NELLA REALIZZAZIONE DI UN COMPONENTE DI FORMA
COMPLESSA NON REALIZZABILE CON TECNICHE CONVENZIONALI.},
	pages = {48--51}
}
@conference{
	11589_52649,
	author = { SPINA R  and  SORGENTE D  and  BRANDIZZI M  and  TRICARICO L },
	title = {Analisi morfologica e metallografica di giunti in lega di titanio saldati con tecnologia ibrida laser CO2-MIG},
	year = {2013},
	booktitle = {Giornate Nazionali di Saldatura 7}
}
@conference{
	11589_23422,
	author = { Spina R  and  Spekowius M  and  Hopmann C },
	title = {Multiscale Modeling of Polymer Crystallization},
	year = {2013},
	booktitle = {Comsol Conference}
}
@conference{
	11589_20248,
	author = { Spina R  and  Spekowius M  and  Küsters K  and  Hopmann C },
	title = {Thermal simulation of polymer crystallization during post-filling},
	year = {2013},
	journal = {KEY ENGINEERING MATERIALS},
	volume = {554-557},
	booktitle = {Esaform 2013},
	pages = {1699--1706}
}