A HOLISTIC APPROACH TO QUALITY MANAGEMENT FOR COMPOSITE FORMING - PowerPoint PPT Presentation

A HOLISTIC APPROACH TO QUALITY MANAGEMENT FOR COMPOSITE FORMING PROCESSES Dr. Farbod Nezami June 2016

Composite Forming: Reliable, fast, effective, but… Geometry Process Source: Airbus, Boeing, ETZ, Daimler • Complex shaped geometries • High lot size • Small sectioned parts • Cost sensible • Packaging- & design demands Fast forming What to do about processes quality? How can we improve the quality of preforms with an holistic quality approach? 1. Parts free of wrinkles and reduction of fiber distortions (“waviness”) 2. Influencing of fiber orientation and shear angles 3. Assess the resulting mechanics 4. Validate our approach? Fuhr | Nezami | Schierle 28.09.2017 | 2

The Complexity of Composite Forming • Textiles show specific forming modes and characteristics. Textiles • Complex Geometries consisting of radii, curvature, edges. Mechanics • Formability can be influenced by Process factors too. Process Geometry • These interactions define the resulting Mechanics of the structure.  Every development has to be regarded as a holistic system of all aspects Fuhr | Nezami | Schierle 28.09.2017 | 3

An Holistic Quality Approach to Preforming Validation Process optimization „Ensuring quality“ Process „Realizing quality“ Mechanics „Analysing quality“ Textiles & Geometry „Planning quality“ Methods Methods Methods Methods Process Selection Active manipulation Optical analysis Composite FEA Material Selection Automation Non-destructive testing Sensitivity studies Process Feasibility Tool design Quality criteria Process factors Draping simulation Draping effects Definition of local quality criteria Fuhr | Nezami | Schierle 28.09.2017 | 4

Material characterization with process induced factors: Shear-Tension Coupling B A Tension free Membrane tension Wrinkles at 55° No wrinkles at 55° Fuhr | Nezami | Schierle 28.09.2017 | 5

Material characterization with process induced factors: Fiber waviness due to interactions Fiber waviness In-plane damage Forming Limit Diagram Fuhr | Nezami | Schierle 28.09.2017 | 6

Definition of a Forming Limit Diagram for Interaction Defects Textiles Process Geometry Fuhr | Nezami | Schierle 28.09.2017 | 7

Recent developments in prediction of fiber waviness • The first chapter of the quality approach showed us that: – There is an interlink between tension (process) and wrinkling (textile) – There is an interaction of layers towards each other which can cause fiber waviness • Draping simulation can be used to investigate the risk of wrinkles and fiber waviness Fuhr | Nezami | Schierle 28.09.2017 | 8

An Holistic Quality Approach to Preforming Validation Process optimization „Ensuring quality“ Process „Realizing quality“ Mechanics „Analysing quality“ Textiles & Geometry „Planning quality“ Methods Methods Methods Methods Active manipulation Optical analysis Composite FEA Process Selection Automation Non-destructive testing Sensitivity studies Material Selection Tool design Quality criteria Process factors Process Feasibility Draping effects Definition of local quality criteria Fuhr | Nezami | Schierle 28.09.2017 | 9

Integration of forming defects of composite forming to FEA analysis 3D Plot of fiber orientation FEA modelling Analysis of forming effects due to forming Draping simulation Nezami, Fuhr, Schierle, Cherif, Middendorf: Holistic development of high quality composite parts based on automated preforming in JEC magazine no. 103, March 2016, Special JEC World Fuhr | Nezami | Schierle 28.09.2017 | 10

An Holistic Quality Approach to Preforming Validation Process optimization „Ensuring quality“ Process „Realizing quality“ Mechanics „Analysing quality“ Textiles & Geometry „Planning quality“ Methods Methods Methods Methods Active manipulation Optical analysis Composite FEA Process Selection Automation Non-destructive testing Sensitivity studies Material Selection Tool design Quality criteria Process factors Process Feasibility Draping effects Definition of local quality criteria Fuhr | Nezami | Schierle 28.09.2017 | 11

Integration of previous steps into process development Mechanical actuators Reduction of interaction force and fiber Reduction of wrinkling due to local application waviness by oscillations of tensile forces Fuhr | Nezami | Schierle 28.09.2017 | 12

Application: Mercedes-Benz AMG Backlid Transfer to Multilayer draping with active active interlayers interlayers 0/90° top layer Cut-out optimization and ply clamping Orientation 0° • Homogenous Blank Holder Force Reduction of the size of wrinkles by 81,5% Cut / Dart • Complete suppression Piezo actuators of interaction based Clamping Clamping for oscillations defects Orientation 45° Different material draw-in and Ply-specific clamping clamping necessary! Fuhr | Nezami | Schierle 28.09.2017 | 13

An Holistic Quality Approach to Preforming Validation Process optimization „Ensuring quality“ Process „Realizing quality“ Mechanics „Analysing quality“ Textiles & Geometry „Planning quality“ Methods Methods Methods Methods Active manipulation Optical analysis Composite FEA Process Selection Automation Non-destructive testing Sensitivity studies Material Selection Tool design Quality criteria Process factors Process Feasibility Draping effects Definition of local quality criteria Fuhr | Nezami | Schierle 28.09.2017 | 14

Validation and Assessment of Measures by Optical Fiber Measurement System Analysis of - Fiber orientations - Gaps - Validation of draping simulation 4 Capturing 3 2 1 Definition of robot coordinates Local Analysis VALIDATION & Definition of critical spots ASSESSMENT Fuhr | Nezami | Schierle 28.09.2017 | 15

Conclusions • To increase quality of parts being produced by composite forming an holistic approach is necessary as interlinks of domains drive overall quality • Early stage material characterization can help to identify dominant quality drivers • In preforming it was found that wrinkles can be suppressed by local tensioning , but risk of interaction defects like fiber waviness can increase hereby. Therefore reduction of normal contact forces is necessary. • This was realized by the utilization of active interlayers which can actively control tensioning and reduce interlayer friction by oscillations • Optical fiber measurement systems were applied to validate the results of draping simulations and assess the quality improvement due to process improvements Fuhr | Nezami | Schierle 28.09.2017 | 16