Holger Seidlitz

Brandenburg University of Technology Cottbus - Senftenberg | BTU · Institute of Lightweight Design and Value-added Management

Carbon fiber-reinforced plastic (CFRP) components are known for their exceptional resilience and ultra-lightweight nature, making them the preferred choice for applications requiring high mechanical loads with minimal weight. However, the intricate and anisotropic structure of CFRP components poses challenges, resulting in expensive repairs and tes...

Fiber-reinforced plastics (FRP) offer great lightweight construction potential. However, the anisotropic high-performance materials can only be fully utilized through the development of material-specific joining processes. A literature study shows that conventional methods such as screwing, riveting and bolting are unsuitable, since the load-bearin...

Modern material-compatible joining methods for fiber-reinforced plastics require the heating of the materials. In order to predict the respective complex temperature fields and curves, the Fraunhofer IAP and the BTU Cottbus-Senftenberg have developed numerical methods, which are able to simulate different radiation sources and process sequences as...

This article portrays the development, adjustment and investigation of the innovative pin welding technology for the joining of thermoplastic fibre/ plastic composites with metallic joining members. In comparison with other procedures, the investigated joining technology offers not only accessibility from one side but also a high lightweight constr...

Neuartige, werkstoffgerechte Fügeverfahren für Faserkunststoffverbunde setzen die Erwärmung der Materialien voraus. Um die damit verbundenen komplexen Temperaturfelder und -verläufe vorherzusagen, haben das Fraunhofer IAP und die BTU Cottbus-Senftenberg numerische Verfahren entwickelt. Mit diesen können auch verschiedene Strahlungsquellen und Proze...

Durch den strukturellen Einsatz von Faser-Kunststoff-Verbunden (FKV) lassen sich hochwertige gewichtsoptimierte Karosserien in Mischbauweise umsetzen. Zur Ausschöpfung des vollen Leichtbaupotentials der FKV müssen werkstoffgerechte Fügeverfahren entwickelt werden. Die untersuchte Pin-Schweißtechnik zur Verbindung von thermoplastischen Organoblechen...

In the liquid composite moulding (LCM) process, fabric is draped over the mould surface and a resin is injected under pressure to develop a composite laminate. Wrinkling is one of the most common flaws that occurs during the draping of the fabric. Wrinkling of the fabric within the composite could severely reduce the quality of the finished composi...

Preforms with large complex geometry, for example, body parts for the automotive industry, are consisted into multiple elements – so-called sub-preforms. Hereby the sub-preforms can be adjusted to different local load cases but joining of these sub-preforms also raises challenges. The preform joints are decisive to the mechanical properties of the...

The paper presents the current volume of international production and global markets of carbon fiber reinforced polymer composites, also regarding the potential development trends. Examples were provided on how to effectively recycle carbon fiber reinforced polymer composites. Legally binding legislation in the EU on polymer composite recycling was...

The paper presents some examples of new technological solutions for the recovery and re-use of recycled carbon fiber in automotive and railway industries, as well as in aviation and wind turbine constructions. The new technologies of fiber recovery that are described can enable the mass-scale use of recycled carbon fiber in the future.

Hot stamping of 22MnB5 steel is know to yield very high strength of up to 1500 MPa depending on the final microstructure. In this work, different microstructures of 22MnB5 steel were produced by quenching with different cooling rates and then utilized to develop Fiber Reinforced Plastic (FRP)-metal hybrid laminates. By developing FRP-metal hybrid l...

In this paper the relationship between surface energy and flexural strength of metal laminate made by reinforcing glass fibre reinforced polymer on steel surfaces was investigated. Sand blasting was performed on 22MnB5 steel surface. This steel was stacked together with layers of unidirectional glass/polyamide-6 prepreg, followed by pressing in a h...

At present plywood structures are used in the loading area of utility structures. Low velocity impact studies on these structures showed cracks on its lower surface. Hence, in the current study low-velocity impact of a lighter honeycomb sandwich structure is investigated to satisfy the needs of the utility vehicle segment. To meet this objective, f...

This study aims to investigate the low-velocity impact response and post-impact flexural behaviour of glass/polyamide-6 (G/PA-6) composite. G/PA-6 composites with a layup configuration of [02,902]s were prepared via press-forming technique. Composite samples were developed using four different processing conditions, by modifying compression pressur...

Composite structure made of thermoset matrix often requires a circular hole to join with a steel or aluminium. Circular holes are introduced into the carbon/epoxy laminates by means of drilling and continuous wave (cw) CO2 laser. In this study, the quality of circular hole produced by drilling and laser processes was investigated by means of delami...

Composite materials have gained popularity in automotive industries due to its lightweight potential, good damping behaviour as well as high strength and stiffness properties. Based on the increase in usage of composites, there is a growing interest for a repair technique in the automotive industry. Along with these raise in demand there comes a ne...

The current trend shows an increasing demand for composites due to their high stiffness to weight ratio and the recent progress in manufacturing and cost reduction of composites. To combine high strength and stiffness in a cost-effective way, composites are often joined with steel or aluminum. However, joining of thermoset composite materials is ch...

Organic sheets made of fiber-reinforced thermoplastics can make a crucial contribution to increase the lightweight potential of a technical design. They show high specific strength- and stiffness properties as well as good damping characteristics, while being able to show a higher energy absorption capacity than comparable metal constructions. In a...

Composite structures used in modern engineering applications are often subjected to circular holes in order to join with metal components via riveting, bolting or pinning joints. These design based holes will interrupt the force flux in the direction of the fibers and create high stress concentrations near the notched area. Objective of the project...

Thermo-mechanically flow-formed joints (FDJ) are an appropriate joining technology to realize high load-bearing multi-material-joints between fiber reinforced thermoplastics and sheet metals, without additional joining components. As in the automotive industry new vehicle and lightweight designs with one-sided accessibility joints are required, the...

Sandwich materials made from corrugated sheet metal provide excellent mechanical properties for lightweight design without using filler material. The increased mechanical properties of these sandwich materials are achieved by the 3-D geometry of the corrugated sheet and the hardening due to pre-forming. In the present study, manufacturing of corrug...

The current trend shows an increasing demand for novel technologies, that facilitate a functional integration of fiber reinforced polymers (FRP) in metal based structures, especially in automotive industry. To comply with the requirements of large-scale production the use of fiber reinforced thermoplastics in form of hybrid metal/composite-laminate...

Multi-layer constructions become more and more relevant in lightweight applications due to their high strength to weight ratio. They offer excellent crash, damping and recycling properties. Also, the morphology of thermoplastic carbon fibre reinforced plastics (CFRP) render them interesting for large scale manufacturing processes. Nevertheless, a m...

Purpose: Carbon fibre reinforced thermoplastics (CFRP) are intensively used in lightweight applications due to their high strength to weight ratio. In addition they offer good crash, damping and recycling properties. On the basis of their morphology they are suitable for large scale manufacturing processes. A major disadvantage consists of its poor...

Multi-material-design (MMD) is commonly realized through the combination of thin sheet metal and fibre reinforced plastics (FRP). To maximize the high lightweight potential of the material groups within a multi-material system as good as possible, a material-adapted and particularly fibre adjusted joining technology must be applied. The present pap...

Increasing mechanical, economic and environmental requirements lead to multi material designs, wherein different classes of materials and manufacturing processes are merged to realize lightweight components with a high level of functional integration. Particularly in automotive industry the use of corresponding technologies will rise in the near fu...

The Institute of Lightweight Structures TU Chemnitz innovative joining technologies for thermoplastic fiber composites and metals are being developed. The reinforcing fibers at the junction of the composite component are reoriented to suit the load, which can achieve high bond strengths to analog designs in nature. The strength-increasing effect wa...

Im Rahmen des DFG-AiF-Clustervorhabens »Großserientaugliche Prozessketten für hochintegrierte Bauteile aus hybriden Faser-Kunststoff / Metall-Verbunden« beschäftigt sich das Fraunhofer IWU, die TU Chemnitz und das IFUM mit der Entwicklung großserienfähiger Prozessketten zur effizienten Verarbeitung von Faser-Kunststoff / Metall (FK/M)-Verbunden zu...

A heavy-duty multi-material-design (MMD) can be realized through the combined use of structured sheet metal and reinforced plastics (FRP). To exploit the high lightweight potential of the various material groups within a multi-material system as efficient as possible, a material-adapted and particularly fiber adjusted joining method must be applied...

The development of a new joining technology, which is used to manufacture high strength hybrid constructions with thermoplastic composites (FRP) and metals, is introduced. Similar to natural regulation effects at trees, fibers around the FRP joint become aligned along the lines of force and will not be destroyed by the joining process. This is achi...

Reliable line production processes and simulation tools play a central role for the structural integration of thermoplastic composites in advanced lightweight constructions. Provided that material- adapted joining technologies are available, they can be applied in heavy-duty multi-material designs (MMD). A load-adapted approach was implemented into...

In fields of mechanical engineering, automotive and aircraft industry the increasing demands for efficient energy processes induce the development of load adjusted multi-material constructions. In particular - due to their higher stiffness, good impact behavior and high load capacity - hybrid structures made of fiber reinforced thermoplastics (FRP)...

The design principle of hybrid construction allows the manufacturing of weight-optimized structures with high stiffness and resistance that meet the increasing demands for energy-efficient production processes and components with high power density. In the automotive industry, this trend is particularly strong. Especially the use of fiber reinforce...

Das an der Professur Strukturleichtbau und Kunststoffverarbeitung (SLK) der TU Chemnitz entwickelte und zum Patent angemeldete thermomechanische Ausformfügeverfahren zum Verbinden von thermoplastischen FKV und Metallen ist auch für die wirtschaftliche Großserienfertigung geeignet. Gekennzeichnet durch kurze Prozesszeiten, kraftflussgerechte und hoc...

Classical spot connections such as screws, bolts or rivets cause considerable concentration of stress at the point of connection in fiber-reinforced plastic (FRP) composites and reduce the loadbearing capacity drastically as a consequence of interruption of the force flux. In FRP/metal hybrid structures in particular, the fiber-reinforced composite...