Sören Bieler

Universität Siegen · Department of Mechanical Engineering

When a vehicle leaves the road, crash barriers stop it and prevent significant damage to the vehicle, its environment, and the occupants. Typically, such protection systems are made of simple steel, but fiber-reinforced composites can efficiently absorb and dissipate the impact energy at high-risk locations. In order to design such protective syste...

Additive manufacturing of pure copper (Cu) via laser-powder bed fusion (L-PBF) is challenging due to the low energy absorptivity under infra-red laser. As a result, 3-dimensional architectures, known for excellent load-bearing and energy absorption capabilities, have not been fabricated in pure Cu, so far. This study, for the first time, Cu lattice...

This paper aims to investigate multiple large-strain topology-optimized structures, by interpreting their overlay as a probability density function. Such a strategy is suited to finding an optimum design of silicon electrodes subject to a random contact. Using this method, and prescribing a zero net-force constraint on the global system, the optimu...

Lattice structures are attractive in additive manufacturing technology as they are small, lightweight, and especially scaleable. Closely spaced diagonal elements absorb energy through elastic and plastic deformation within a lattice, but the performance depends on many factors like design, material properties, printing process, post‐treatment, etc....

Lattice structures composed of periodic solid frames and pores can be utilized in energy absorption applications due to their high specific strength and large deformation. However, these structures typically suffer from post-yield softenings originating from the limited plasticity of available material choices. This study aims to resolve such an is...

The paper deals with experiments on 3D printed lattices in a Split Hopkinson Pressure Bar. An energy-based evaluation of the measured wave signals enables us to compare the damping properties of two different copper lattice structures.

The usage of resin-based materials for 3D printing applications has been growing over the past decades. In this study, two types of resins, namely a MMA-based resin and an ABS-based tough resin, are subjected to compression tests on a split Hopkinson pressure bar to deduce their dynamic properties under high strain rate loading. Two Hopkinson bar s...

The Split‐Hopkinson Pressure Bar (SHPB) is a common experimental setup to investigate the dynamic properties of materials. For soft materials the SHPB setup has to be customize using plastic bars. Because such bars show wave attenuation and dispersion, the measured wave signals have to be corrected. In this study a method of signal correction by me...

The wave propagation in a group of soft resin based (3d printed) materials is investigated by using a Split Hopkinson Bar test. The principal assumptions and the role of pulse shaping, as an approach to achieve constant strain rates and dispersion reduction, is discussed. The experimental stress‐strain curves, gained by aluminium Split Hopkinson ba...

The wave propagation in a group of soft resin based (3d printed) materials is investigated by using a Split Hopkinson Bar setup. The principal assumptions and the role of pulse shaping, as an approach to achieve constant strain rates and dispersion reduction, is discussed. The measured dynamic elastic modulus is presented and indicates that flexibl...