Christian Willberg

Prof. Dr. Christian Willberg

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Research Focus & Metrics

Academic Career Length

18Years (2009-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 October 2012 in Computer Methods in Applied Mechanics and Engineering
Verified
Journal Article
Closed access
CWChristian Willberg
Christian Willberg
SDS. Duczek
S. Duczek
JPJ.M. Vivar Perez
J.M. Vivar Perez
DSD. Schmicker
D. Schmicker
UGU. Gabbert
U. Gabbert

Verified
Journal Article
Open access
PDF file
FHFalk Heinecke
Falk Heinecke
CWChristian Willberg
Christian Willberg
The automated fiber placement process (AFP) enables the manufacturing of large and geometrical complex fiber composite structures with high quality at low cycle times. Although the AFP process is highly accurate and reproducible, manufacturing induced imperfections in the produced composite structure occur. This review summarizes and classifies typical AFP-related manufacturing defects. Several methodologies for evaluating the effects of such manufacturing defects from the literature are reviewed. This review paper presents recent scientific contributions and discusses proposed experimental and simulation-based methodologies. Among the identified ten defect classes, gaps and overlaps are predominant. This paper focuses then on methods for modelling and assessing gaps and overlaps. The state of the art in modelling gaps and overlaps and assessing their influence on mechanical properties is presented. Finally, research gaps and remaining issues are identified.

1 January 2015 in Applied Mechanics Reviews
Verified
Journal Article
Closed access
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CWChristian Willberg
Christian Willberg
SDSascha Duczek
Sascha Duczek
JVJ. M. Vivar-Perez
J. M. Vivar-Perez
ZAZ. A. B. Ahmad
Z. A. B. Ahmad
This paper reviews the state-of-the-art in numerical wave propagation analysis. The main focus in that regard is on guided wave-based structural health monitoring (SHM) applications. A brief introduction to SHM and SHM-related problems is given, and various numerical methods are then discussed and assessed with respect to their capability of simulating guided wave propagation phenomena. A detailed evaluation of the following methods is compiled: (i) analytical methods, (ii) semi-analytical methods, (iii) the local interaction simulation approach (LISA), (iv) finite element methods (FEMs), and (v) miscellaneous methods such as mass–spring lattice models (MSLMs), boundary element methods (BEMs), and fictitious domain methods. In the framework of the FEM, both time and frequency domain approaches are covered, and the advantages of using high order shape functions are also examined.

14 June 2012 in Smart Materials and Structures
Verified
Journal Article
Closed access
CWChristian Willberg
Christian Willberg
SKS Koch
S Koch
GMG Mook
G Mook
JPJ Pohl
J Pohl
UGU Gabbert
U Gabbert

28 April 2020 in Applied Sciences
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Journal Article
Open access
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Jochen MollJochen Moll
Jochen Moll
CKChristian Kexel
Christian Kexel
JKJens Kathol
Jens Kathol
CFClaus-Peter Fritzen
Claus-Peter Fritzen
MMMaria Moix-Bonet
Maria Moix-Bonet
AHAxel Herrmann
Axel Herrmann
The third dataset dedicated to the Open Guided Waves platform aims at carbon fiber composite plates with an additional omega stringer at constant temperature conditions. The two structures used in this work are representative for real aircraft components. Comprehensive measurements were recorded in order to study (I) the impact of the omega stringer on guided wave propagation, and (II) elliptical reference damages of different sizes located at three separate positions on the structure. Measurements were recorded for narrowband excitation (5-cycle toneburst with varying carrier frequencies) and broadband excitation (using chirp waveforms). The paper presents the results of a technical validation including numerical modelling, and enables further research, for example related to probability of detection (POD) analysis.