# package inputenc error : the keyboard character used is undefined

I have a simple text line that I get the above error in it , I don't see anything strange in the line , shall you please help me about it ? I am sure it's not about reading the help again ! thank you so much

\documentclass[11pt,a4paper,twoside,openright]{report}

\usepackage{setspace}
\usepackage{graphicx}
\usepackage{tabularx}
\usepackage{tabu}
\usepackage{subfigure}
\usepackage{afterpage}
\usepackage{amsmath,amssymb}
\usepackage{rotating}
\usepackage{fancyhdr}
\usepackage[scriptsize]{caption}
\hyphenation{a-gen-tiz-za-zio-ne}
\usepackage{float}
\usepackage[parfill]{parskip}
\usepackage{multicol}
\usepackage{siunitx}
\usepackage{amsmath}

\graphicspath{ {images/} }

\usepackage[a4paper,lmargin=2cm,rmargin=2cm]{geometry}

\newcommand*{\diff}{\mathop{}\!\mathrm{d}}

\newcommand*{\var}[1]{\texttt{#1}}

\usepackage[USenglish]{babel}
\usepackage[latin1]{inputenc}
\renewcommand{\captionfont}{\normalfont \sffamily \itshape \small}

\pagestyle{empty}

\begin{document}

F.W.Zok \cite{R34} has analyzed metalic sandwich panels with textile cores  subject to combined bending and shear and then designed for minimum weight. Basic results for the weight benefits relative to solid plates are presented, with emphasis on restricted optimizations that assure robustness (non-catastrophic failure) and acceptable thinness. Select numerical simulations are used to check the analytical results and to explore the role of strain hardening beyond failure initiation. Comparisons are made with competing concepts, especially honeycomb and truss core systems. It is demonstrated that all three systems have essentially equivalent performance. The influence on the design of a concentrated compressive stress that might crush the core has been explored and found to produce relatively small effect over the stress range of practical interest. “Angle ply” cores with members in the $\pm \ang{45}$ orientation are found to be near optimal for all combinations of bending, shear and compression.

\end{document}

and also the reference R34 in the code is :

@Article{R34,
Title                    = {Design of metallic textile core sandwich panels },
Author                   = {F.W. Zok and H.J. Rathbun and Z. Wei and A.G. Evans},
Journal                  = {International Journal of Solids and Structures },
Year                     = {2003},
Number                   = {21},
Pages                    = {5707 - 5722},
Volume                   = {40},

Doi                      = {http://dx.doi.org/10.1016/S0020-7683(03)00375-5},
ISSN                     = {0020-7683},
Keywords                 = {Sandwich panels},
Url                      = {http://www.sciencedirect.com/science/article/pii/S0020768303003755}
}
• Given the above code, for what line is the error reported? – jon Apr 4 '15 at 18:47
• Could you please tell us what R34 looks like? Your code compiles fine for me but obviously the reference is not populated. – Christopher Apr 4 '15 at 18:50
• If you copy the above to a new file and run it locally to you get an error? If not, the example as posted does not demonstrate the problem, and you need to copy more text from the original so that it does. – David Carlisle Apr 4 '15 at 19:08
• It depends whether you enjoy nasty surprises or not. – cfr Apr 4 '15 at 20:02
• The non-ASCII quotation marks around "Angle ply" might be the cause of the trouble. And the encoding option latin1 can be incorrect, e.g. if the file is encoded in UTF-8. – Heiko Oberdiek Apr 4 '15 at 21:05

try this:

\documentclass[11pt,a4paper,twoside,openright]{report}

\usepackage{setspace}
\usepackage{graphicx}
\usepackage{tabularx}
\usepackage{tabu}
\usepackage{afterpage}
\usepackage{amsmath,amssymb}
\usepackage{rotating}
\usepackage{fancyhdr}
\usepackage[scriptsize]{caption}
\hyphenation{a-gen-tiz-za-zio-ne}
\usepackage{float}
\usepackage[parfill]{parskip}
\usepackage{multicol}
\usepackage{siunitx}
\usepackage{amsmath}

\graphicspath{ {images/} }

\usepackage[a4paper,lmargin=2cm,rmargin=2cm]{geometry}

\newcommand*{\diff}{\mathop{}\!\mathrm{d}}

\newcommand*{\var}[1]{\texttt{#1}}

\usepackage[USenglish]{babel}
\usepackage[latin1]{inputenc}
\renewcommand{\captionfont}{\normalfont \sffamily \itshape \small}

\pagestyle{empty}

\begin{document}

F.W.Zok \cite{R34} has analyzed metalic sandwich panels with textile cores  subject to combined bending and shear and then designed for minimum weight. Basic results for the weight benefits relative to solid plates are presented, with emphasis on restricted optimizations that assure robustness (non-catastrophic failure) and acceptable thinness. Select numerical simulations are used to check the analytical results and to explore the role of strain hardening beyond failure initiation. Comparisons are made with competing concepts, especially honeycomb and truss core systems. It is demonstrated that all three systems have essentially equivalent performance. The influence on the design of a concentrated compressive stress that might crush the core has been explored and found to produce relatively small effect over the stress range of practical interest. Angle ply'' cores with members in the $\pm \ang{45}$ orientation are found to be near optimal for all combinations of bending, shear and compression.

\end{document}

it was the quote characters that Angle ply had. this is a pretty common encoding mistake with copy-paste. in the future, please post a minimal working example - had you tried to put one together, you probably would have found the problem in the process : ).

also, my obsessive-compulsive tendencies beg that you remove your preamble line of \usepackage{amsmath} since you already have \usepackage{amsmath,amssymb} above it.

• thanks a lot, I corrected it and removed the repeated package as well – Farzad64 Apr 4 '15 at 21:38
• Can you please kick out the obsolete for ten years-subfigure? It doesn't seem to be relevant anyway. – Johannes_B Apr 7 '15 at 12:11
• @Johannes_B ha, happily; it is done. i will leave the disclaimer that i asked the op repeatedly for a mwe and did not receive one. the code posted is not intended to be an example of what code should look like. – aeroNotAuto Apr 7 '15 at 12:45
• Seeing this in an asnwer is bugging me anyway. :-) I know that this is just due to a lack of a real MWE <- Once again a link for @Farzad64 :-) – Johannes_B Apr 7 '15 at 12:50
• @Johannes_B yea i hear ya. i'm sure somebody, from a search engine that hasn't been invented yet, will cut and paste this someday, so i see the merit in removing the most egregious code. – aeroNotAuto Apr 7 '15 at 12:55