Ultra high strength steel sandwich for lightweight applications

Abstract

Methods for reducing weight of structural elements are important for a sustainable society. Over the recent years ultra high strength steel (UHSS) has been a successful material for designing light and strong components. Sandwich panels are interesting structural components to further explore areas where the benefits of UHSS can be utilized. The specific properties of sandwich panels make them suitable for stiffness applications and various cores have been studied extensively. In the present work, bidirectionally corrugated UHSS cores are studied experimentally and numerically. A UHSS core is manufactured by cold rolling and bonded to the skins by welding. Stiffness is evaluated experimentally in three-point bending. The tests are virtually reproduced using the finite element method. Precise discretization of the core requires large amounts of computational power, prolonging lead times for sandwich component development, which in the present work is addressed by homogenization, using an equivalent material formulation. Input data for the equivalent models is obtained by characterizing representative volume elements of the periodic cores under periodic boundary conditions. The homogenized panel reduces the number of finite elements and thus the computational time while maintaining accuracy. Numerical results are validated and agree well with experimental testing. Important findings from experimental and simulation results show that the suggested panels provide superior specific bending stiffness as compared to solid panels. This work shows that lightweight UHSS sandwiches with excellent stiffness properties can be manufactured and modeled efficiently. The concept of manufacturing a UHSS sandwich panel expands the usability of UHSS to new areas.

Numerical evaluation of lightweight ultra high strength steel sandwich for energy absorption

“…PBCs are necessary for periodicity to be maintained and to not overpredict stiffness when characterizing a single RVE, see e.g. Hammarberg et al [26], Suquet [32], Xia et al [33], Omairey et al [34]. A short description of PBC is given in Sect.…”

“…The increased performance of the sandwich, with respect to crashworthiness, was evident. Hammarberg et al [26] manufactured a UHSS sandwich panel with a bidirectionally corrugated core, intended for stiffness applications. Homogenization of the core was carried out by analyzing a representative volume element under periodic boundary conditions, reducing computational time with maintained accuracy.…”

A homogenization method for natural frequencies and damping analysis of composite pyramidal lattice truss sandwich structures based on representative volume elements

“…21 In recent years, a homogenization method based on the RVE and FEM has been developed to calculate the linear, nonlinear, and post-buckling behavior of sandwich structures. [21][22][23][24][25][26][27][28][29] In this method, a unit cell of the periodic sandwich structure is selected as the RVE, and the reaction of the RVE are obtained to calculate the stiffness matrix of the single-layer model. While the RVE/FEM method has been used to homogenize various sandwich panels, it has not been applied to the calculation of vibration and damping.…”

Improving the Microstructure and Mechanical Properties of Laser Welded Al-Si Coated 22MnB5/ Galvanized Steel Joint Added by Nickel

“…The increasing popularity of automotive lightweight design concepts has greatly promoted the application and extensively of ultra-high strength steels (UHSS) [1][2][3]. 22MnB5 steel is an ordinary steel with an ultimate tensile strength of 1.5GPa after hot stamping.…”